3'.52- 


^ 


HAWAII  AGRICULTURAL  EXPERIMENT  STATION 
HONOLULU,  HAWAH 

Under  the  supervision  of  the 
UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 


BULLETIN  No.  52 


MANGANESE  CHLOROSIS  OF  PINEAPPLES: 
ITS  CAUSE  AND  CONTROL 


BY 


MAXWELL  O.  JOHNSON,  Chemist 


Issued  July,  1924 


I 


\*A 


"v^rm* 


WASHINGTON 

GOVERNMENT  PRINTING   OFFICE 

1924 


HAWAII  AGRICULTURAL  EXPERIMENT  STATION,  HONOLULU. 

[Under  the  supervision  of  the  Office  of  Experiment  Stations,  United  States  Department  of  Agriculture. 1 

E.  W.  Allen,  Chief,  Office  of  Experiment  Stations. 

Walter  H.   Evans,   Chief,   Division  of  Insular  Stations,  Office  of  Experiment 
Stations. 


STATION  STAFF. 

J.  M.  Westgate,  Agronomist  in  Charge. 

W.  T.  Pope,  Horticulturist. 

H.  L.  Chung,  Specialist  in  Tropical  Agronomy. 

J.  C.  Ripperton,  Chemist. 

M.  O.  Johnson,1  Chemist. 

R.  A.  Gofp,  In  Charge  of  Glenwood  Substation  and  Extension  Agent  for  Island  of 

Hawaii. 
Nellie  A.  Russell,2  Collaborator  in  Home  Economics. 
Mabel  Greene,  Boys*  and  Girls'  Club  Leader. 


Resigned,  effective  Mar.  20,  1919.  *  Resigned,  effective  June  30,  1923. 


Bui.  52,  Hawaii  Agr.  Expt.  Station. 


PLATE  I. 


Wkl*(i\> 


ik 


Main  Field  Experiment  Showing  Benefits  Produced  with  Iron  Sulphate 
Solution,    plants  on  left  not  Sprayed,  Those  on  Right  Sprayed. 


HAWAII  AGRICULTURAL  EXPERIMENT  STATION 

HONOLULU,  HAWAII 

Under  the  supervision  of  the 
UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 


BULLETIN  No.  52 


Washington,  D.  C.  V  July,  1924 


MANGANESE  CHLOROSIS  OF  PINEAPPLES:  ITS 
CAUSE  AND  CONTROL. 


Bv  M.  O.  Johnson,1  Chemist. 


CONTENTS. 


Page.  Page. 


Yellowing  of  pineapples  on  manganese  soils I 

Previous  investigations  en  manganese. ..  2 

Investigations  on  lime-induced  chlorosis.. 5 

Status  of  manganese  problem  when  the  present 

investigations  were  undertaken 6 

The  manganiferous  soils  and  their  effect  on 

pineapple  and  other  plants 7 


An  explanation  of  the  physiological  effects  of 

manganese  on  plants.. 24 

A  successful  treatment 27 

Practical  tests  of  the  method  of  spraying 30 

Practical  advice  regarding  the  treatment 34 

Genera]  summary  and  conclusions 35 

Literature  cited ■ 36 


YELLOWING  OF  PINEAPPLES  ON  MANGANESE  SOILS. 

The  yellowing  of  pineapples  grown  on  the  manganese  soils  of  the 
Hawaiian  Islands  was  a  serious  problem  to  pineapple  growers  for 
many  years.  Large  areas  of  these  black  or  dark  manganese  soils 
are  found  in  the  chief  pineapple-growing  district  lying  on  the  sloping 
plateau  between  the  Koolau  and  Waianae  Mountain  ranges  on  the 
island  of  Oahu.  Such  soils  also  occur  in  the  very  large  potential 
pineapple  areas  on  the  islands  of  Molokai  and  Lanai,  and  to  some 
extent  on  the  islands  of  Kauai  and  Maui.  None  of  these  areas  could 
be  profitably  utilized  until  a  solution  of  the  manganese  problem  was 
found. 

When  pineapple  plantings  were  first  being  extensively  made  in 
1902,  prospective  growers  eagerly  sought  the  dark  soils,  being  influ- 
enced by  the  color  which  was  thought  to  be  indicative  of  great  fer- 
tility. It  was  soon  discovered  that  the  pineapples  on  these  soils 
suffered  serious  injury,  a  trouble  which  locally  became  known  as 
i4  pineapple  yellows/'  or  "manganese  yellows." 

The  most  pronounced  characteristic  by  which  these  pineapple 
plants  were  differentiated  from  normal  plants  was  a  gradual  fading 
of  the  leaves  until  the  whole  plant  assumed  a  yellowish-white  appear- 
ance. Blanching  of  the  leaves  occurred  at  any  period  of  growth, 
but  usually  started  in  three  to  six  months  after  the  time  of  planting. 

i  The  writer  wishes  to  thank  J.  M.  Westgate,  agronomist  in  charge  of  the  Hawaii  Agricultural  Experiment 
Station,  for  heartiest  support  and  encouragement  in  this  investigation,  and  J.  T.  Whitmore,  S.  T.  Hoyt, 
and  H.  Blomfield  Brown,  of  the  Hawaiian  Pineapple  Co.,  for  their  generous  cooperation  and  help. 


2  BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 

In  many  cases  the  plant  ceased  growth  and  began  to  die  back  from 
the  tips  of  the  leaves.  During  the  earlier  stages  of  development  the 
fruit  was  reddish-pink  in  color  instead  of  deep  green,  and  in  the 
ripened  stage  the  flesh  was  not  only  hard  and  white  instead  of  straw- 
colored,  but  it  also  lacked  flavor  and  contained  considerable  acid. 
Many  of  the  fruits  cracked  open  and  decayed  before  ripening. 

Preliminary  reports  (24,  25,  26)  2  of  the  writer's  investigations  on 
the  manganese  problem  were  published  in  order  to  make  available  as 
quickly  as  possible  information  concerning  the  simple  remedy  dis- 
covered for  the  "  manganese  yellows."  This  remedy,  consisting  of  in- 
expensive sprayings  with  solutions  of  iron  sulphate,  met  with 
immediate  success  and  is  now  being  used  on  thousands  of  acres  of 
Hawaiian  pineapples.  Considerably  over  half  of  Hawaii's  production 
of  canned  pineapples  is  borne  by  sprayed  plants.  This  bulletin  gives 
a  rather  detailed  account  of  the  results  obtained  and  also  of  the 
manner  in  which  manganese  induces  chlorosis. 

REVIEW  OF  PREVIOUS  INVESTIGATIONS  ON  MANGANESE. 

Manganese  is  found  in  small  quantities  in  most  soils  and  in  many 
plants.  Certain  forest  trees,  notably  the  conifers,  contain  rather 
large  amounts  of  manganese.  Schroeder  (40,  41)  reported  in  1878 
the  occurrence  of  35.53  per  cent  Mn304  in  the  ash  of  pine  needles 
and  of  41.23  per  cent  in  the  ash  of  pine  bark.  Many  experiments 
have  been  made  with  manganese  in  different  forms  as  a  fertilizer. 
Kelley  (32)  and  Skinner  and  Sullivan  (43)  give  extensive  reviews  of 
these  experiments.  It  is  not  necessary  to  refer  to  these  in  detail, 
as  they  were  carried  on  in  connection  with  crop  production,  and 
the  results  obtained  do  not  show  that  manganese  is  valuable  as  a 
fertilizer.  Some  investigators  have  found  a  stimulation  of  growth 
from  the  application  of  small  quantities  of  various  manganese  com- 
pounds, while  others  have  found  no  effects  and  even  a  retardation 
of  growth.  It  appears  generally  that  the  application  of  large  amounts 
of  manganese  produces  a  toxic  effect. 

The  chemical  similarity  of  manganese  and  iron  has  suggested  a 
number  of  interesting  experiments  dealing  with  the  physiological 
effects  of  manganese.  Unsuccessful  attempts  were  made  by  Sachs 
(38) ,  Birner  and  Lucanus  (7) ,  and  Wagner  (45)  to  substitute  manga- 
nese for  iron  in  the  production  of  chlorophyll,  and  an  injurious  effect 
was  noted  when  manganous  and  manganic  phosphates  were  sus- 
pended in  culture  solutions. 

Since  the  discovery  by  Bertrand  (5,  6)  that  manganese  occurs  in 
the  ash  of  oxidizing  enzyms,  the  physiological  effects  of  manganese 
on  plants  have  been  generally  attributed  to  some  influence  of  the 
manganese  on  these  enzyms. 

Loew  and  Sawa  (33)  in  1902  observed  a  yellowing  of  pea  plants, 
barley,  and  soy  beans  in  water-culture  experiments  with  solutions  to 
which  small  amounts  of  manganese  sulphate  had  been  added.  The 
addition  of  manganese  sulphate  to  the  usual  iron-containing  nutrient 
solution  caused  an  increased  growth  in  which  yellowing  later  took 
place.  This  yellowing  is  thought  to  have  been  due  to  the  increased 
activity  of  the  oxidizing  enzyms.  They  conclude  that  "  manganese 
exerts  in  moderate  quantity  an  injurious  action  on  plants,  consisting 

2  Reference  is  made  by  number  (italic)  to  "Literature  cited,"  p.  36. 


MANGANESE    CHLOROSIS    OF   PINEAPPLE.  3 

in  the  bleaching  out  of  the  chlorophyll.  The  juices  of  such  plants 
show  more  intense  reactions  for  oxidase  and  peroxidase  than  the 
healthy  control  plants." 

Aso  (1)  in  similar  water  cultures  with  young  radish,  barley,  and 
wheat  plants  observed  a  yellowing  with  solutions  containing  (a)  0.02 
percent  MnS04  + trace  of  FeS04,  (b)  0.02  per  cent  MnSO4  +  0.02 
per  cent  FeS04  in  comparison  with  (c)  0.02  per  cent  FeS04  and  in 
these  three  solutions  diluted  with  10  times  their  volume  of  water. 
The  ordinary  mineral  constituents  were  supplied.  When  the  solu- 
tion containing  manganese  sulphate  and  only  a  trace  of  ferrous  sul- 
phate was  diluted  10  times  the  yellowing  suggested  a  lack  of  iron. 
JPea  shoots  grown  during  the  first  stage  of  development  in  solutions 
containing  no  mineral  salts  and  only  0.002  per  cent  ferrous  sulphate 
and  manganous  sulphate  singly  and  in  combination  found  the  great- 
est stimulation  with  the  manganous  sulphate.  No  yellowing  was 
observed  during  this  first  stage  of  development.     Aso  concludes  that: 

(1)  Manganese  salts  exert  on  the  one  hand  an  injurious  action  and  on  the 
other  a  stimulant  influence  on  plants;  with  increased  dilution  the  former  dimin- 
ishes while  the  latter  increases.  Thus  a  dilution  can  be  reached  in  which  only 
the  favorable  action  of  manganese  becomes  obvious. 

(2)  Manganous  sulphate  added  in  a  dilution  of  0.002  per  cent  to  culture  solu- 
tions exerted  a  stimulant  action  upon  radish,  barley,  wheat,  and  pea.  Iron 
seems  to  counteract  to  a  certain  degree  the  action  of  the  manganese. 

(3)  The  intensity  of  the  color  reactions  of  the  oxidizing  enzyms  of  the  man- 
ganese plants  exceeds  that  of  the  control  plants. 

That  the  injurious  effects  of  manganese  may  be  due  to  a  depressed 
assimilation  of  iron  does  not  appear  to  be  suspected  in  the  later  work 
of  Aso  (2,  3)  and  other  investigators. 

Katayama  (27)  found  an  increase  in  yield  of  barley  when  small 
amounts  of  manganous  sulphate  were  used.  Large  amounts  of  man- 
ganese retarded  growth. 

In  1907  Salomone  (39)  published  the  results  of  an  extensive  inves- 
tigation with  various  salts  and  oxids  of  manganese.  A  slight  yellow- 
ing was  observed  in  wheat  in  field  experiments  when  small  quantities 
of  the  oxids  were  used,  but  the  final  yield  was  increased.  Serious 
injury  was  observed  when  manganese  as  manganous  sulphate  was 
applied  at  a  rate  greater  than  50  kilograms  per  hectare,  and  the 
plants  died  when  still  larger  quantities  were  used.  The  toxic  effects, 
due  to  manganese,  seem  to  be  similar  to  those  which  the  pineapple 
plant  suffers  on  manganiferous  soil,  i.  e.,  a  yellowing,  disorganization 
of  the  chlorophyll  bodies,  and  other  physiological  derangements. 
The  crop  was  injured  also  when  these  plats  were  planted  to  wheat 
for  the  second  time.  It  is  significant  that  lime  and  basic  slag  appli- 
cations did  not  diminish  this  toxic  effect  as  was  also  the  case  in  the 
liming  experiments  on  the  manganiferous  soils  of  Oahu. 

Salomone  also  found  that  fcpavy  applications  of  various  manganese 
compounds  caused  the  death  of  bean  plants  which  were  grown  in 
boxes  and  that  the  toxicity  of  manganese  was  greater  where  manga- 
nese functioned  as  an  electronegative  element. 

Hall  (21)  thinks  that  in  field  experiments  the  stimulating  action  of 
manganese  is  due  to  some  indirect  effect  on  the  dormant  bases  of  the 
soil  rather  than  to  a  direct  effect  of  the  manganese.  He  does  not, 
however,  consider  this  point  established. 


4  BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 

Bernardini  (4)  in  1910  concluded  from  a  series  of  experiments  that 
manganese  has  a  catalytic  effect  on  soils,  increasing  their  oxygen- 
absorbing  power  and  possibly  influencing  the  soil  bacteria.  Juclging 
from  the  results  of  various  experiments  in  which  solutions  of  manga- 
nous  chloric!  effected  replacement  of  large  amounts  of  lime  and  mag- 
nesia in  certain  silicates,  he  thinks  that  the  stimulating  effect  of 
applied  manganese  may  be  due  to  some  indirect  effect  of  replacement 
rather  than  to  any  physiological  action. 

Brenchley  (8)  in  water  cultures  of  barley  found  a  stimulating  effect 
with  very  small  amounts  of  manganous  sulphate,  but  noted  that  the 
plants  turned  brown  and  died  with  large  quantities. 

Kelley  (28,  29,  30,  31 )  was  the  first  to  publish  results  showing  that 
there  is  a  close  correlation  between  the  yellowing  of  pineapples  in 
Hawaii  and  an  abnormal  amount  of  manganese  in  the  soil. 

Wilcox  and  Kelley  (Jfi)  found,  in  their  study  of  the  effects  of  man- 
ganese on  pineapple  plants  and  the  ripening  of  the  fruits,  that  sec- 
tions showed  under  the  microscope  a  fading  of  the  chlorophyll  and  a 
destruction  of  the  organized  structure  of  the  chloroplasts. 

In  1912  Kelley  (32)  published  the  results  of  an  extensive  investiga- 
tion of  the  effects  of  these  manganiferous  soils  of  Oahu  on  the  pine- 
apple and  other  plants.  Notes  were  made  comparing  the  appear- 
ance and  growth  of  field  plants  in  manganiferous  soil  with  plants  in 
normal  soil,  and  likewise  of  plants  in  pots  of  manganese  soil  with 
those  in  pots  of  normal  soil. 

From  this  investigation  Kelley  concluded  that — 

Various  plants  when  grown  on  manganiferous  soil  are  affected  differently. 
Some  species  are  stunted  in  growth  -and  die  back  from  the  tips  of  the  leaves, 
which  turn  yellow  or  brown  and  frequently  fall  off,  and  a  general  unhealthy 
appearance  results.  Other  species  appear  to  be  unaffected  and  so  far  as  can  be 
judged  vegetate  normally  in  the  presence  of  manganese.  Microscopic  investi- 
gations have  shown  that  in  certain  instances  the  protoplasm  undergoes  changes. 
Occasionally  it  draws  away  from  the  cell  walls,  the  nuclei  become  brown,  and 
plasmolysis  takes  place.     *     *     * 

From  the  ash  analysis  it  was  found  that  manganese  was  absorbed  in  consider- 
able quantities,  and  in  nearly  every  instance  was  greater  in  the  plants  from 
manganiferous  soil.  The  ash  analysis  also  shows  that  a  disturbance  of  the 
mineral  balance  takes  place.  The  percentage  of  lime  is  increased,  while  the 
absorption  of  magnesia  and  phosphoric  acid  is  decreased.     *     *     * 

From  these  evidences  we  may  believe  that  the  effects  of  manganese  are  largely 
indirect  and  are  to  be  explained  on  the  basis  of  its  bringing  about  a  modification 
in  the  osmotic  absorption  of  lime  and  magnesia,  and  that  the  toxic  effects  are 
chiefly  brought  about  through  this  modification,  rather  than  as  a  direct  effect 
of  the  manganese  itself. 

In  1914  Skinner  and  Sullivan  et  al.  (43)  published  results  of  pot 
and  field  experiments  in  which  compounds  of  manganese  were 
applied  as  fertilizers.  Changes  were  observed  in  the  oxidative 
power  of  the  soils  as  a  result  of  the  manganese.  Manganese  in  small 
quantities  had  a  stimulating  effect  in  pot  experiments  with  an  unpro- 
ductive soil,  but  resulted  in  no  increase  in  growth  with  a  productive 
soil.  A  five-year  field  test  with  an  acid  soil  to  which  manganous 
sulphate  was  added  at  the  rate  of  50  pounds  per  acre  showed  a 
harmful  effect  on  each  of  the  crops  grown.  In  regard  to  the  toxic 
effects  of  large  amounts  of  manganese,  Skinner  and  Sullivan  made 
the  following  statement : 

Where  manganese  has  been  of  little  value  or  has  given  decreased  yields,  con- 
ditions were  such  that  stimulating  actions  on  plant  and  microorganisms  did  not 
come  into  play,  or,  on  account  of  the  acid  reaction  of  the  soil,  the  effect  of  the 


MANGANESE    CHLOROSIS    OF    PINEAPPLE.  O 

stimulation  led  to  reduction  processes  being  predominant.  Large  applications 
of  manganese  have  been  found  injurious,  undoubtedly  because  of  excessive 
stimulation  and  excessive  oxidation  in  microorganisms  and  in  the  plant,  with  a 
resulting  change  in  the  biochemical  activities  of  plant  and  microorganisms  and 
in  the  conditions  of  inorganic  and  organic  soil  constituents,  the  ultimate  result 
of  which  change  is  injurious  to  the  growing  crop. 

Later  in  1916,  Skinner  and  Reid  (J$)  found  that  the  productivity 
of  the  soil  was  increased  by  manganese  when  the  plats  on  which  the 
experiments  were  conducted  were  limed.     They  state  that — 

The  action  of  manganese  in  the  acid  soil  was  probably  to  stimulate  the  life 
processes  in  the  soil,  acting  on  the  organic  matter  in  such  a  way  as  to  produce 
changes  which  resulted  in  a  lessened  crop-producing  power,  while  its  action  in 
the  neutralized  soil  was  such  as  to  stimulate  oxidation  and  other  biological 
processes,  acting  on  the  organic  soil  constituents  and  producing  changes  favor- 
able to  the  growing  plants. 

Pugliese  {37)  from  water-culture  experiments  similar  to  those  of 
Loew  and  Sawa  suspected  an  antagonism  between  iron  and  man- 
ganese anil  stated  that  there  was  an  optimum  ratio  which  he  gave 
as  1  :  2..J. 

McCool  {36)  found  that- 
Pure  solutions  of  manganese  salts  are  extremely  poisonous  to  pea  and  wheat 
seedlings.  The  degree  of  toxicity  is  greatly  reduced  by  full  nutrient  solutions 
and  by  soil  cultures.  The  injurious  action  of  the  manganese  ion  is  manifested 
mainly  toward  the  tops  of  plants.  Chlorosis  of  the  leaves  is  the  first  indication 
of  an  overdose  of  manganese.  Manganese  is  less  injurious  to  plants  grown  in 
the  dark  than  to  those  grown  in  the  light.  Calcium,  potassium,  sodium,  and 
magnesium  ions  are  each  effective  in  counteracting  the  poisonous  action  of 
manganese.  Mutual  antagonism  exists  between  the  manganese  ion  and  each  of 
the  following:  Potassium,  sodium,  and  magnesium. 

Tottingham  and  Beck  (4-0  suspected  an  antagonism  toward  iron 
similar  to  those  stated  above  for  potassium,  sodium,  and  magnesium. 

Brown  and  Minges  (9)  in  1916  believed  that  the  effects  of  manga- 
nese applications  to  the  soil  may  be  ascribed  to  their  effect  on  ammo- 
nification  and  nitrification. 

Funchess  (IS)  found  that  the  nitrification  of  dried  blood  on  certain 
Alabama  soils  produced  soluble  manganese  salts  which  were  toxic  in 
effect. 

Deatrick  {12)  found  in  high  concentrations  that  manganese  salts 
exerted  a  toxic  effect,  and  in  lower  concentrations  marked  stimulation. 
"The  toxic  influence  results  in  the  browning  of  the  roots  and  the 
bleaching  of  the  leaves." 

PREVIOUS  INVESTIGATIONS  ON  LIME-INDUCED  CHLOROSIS. 

It  has  been  known  for  many  years  that  some  plants  become  affected 
with  chlorosis  or  bleaching  when  they  are  grown  on  soils  containing 
very  large  amounts  of  carbonate  of  lime.  Some  species  of  grape- 
vines which  grow  on  certain  highly  calcareous  soils  of  France  are 
probably  the  best-known  examples  of  chlorosis.  This  bleaching  has 
been  attributed  by  some  investigators  to  lack  of  potash  in  the  soil 
or  to  the  physical  condition  of  the  soil,  but  the  general  conclusion 
seems  to  be  that  the  condition  is  brought  about  by  lack  of  iron  in 
the  plants,  due  to  excessive  amounts  of  carbonate  of  lime  in  the  soil. 
Manganese  has  not  been  associated  with  this  condition. 

Gile  and  Ageton  {16)  have  probably  made  the  latest  and  most 
thorough  investigation  of  such  highly  calcareous  soils.     In  1911  Gile 


6  BULLETIN    52,    HAWAII   EXPERIMENT    STATION. 

(IS)  found  chlorosis  to  occur  on  certain  areas  of  Porto  Rican  soils 
and  attributed  it  to  an  excessive  amount  of  carbonate  of  lime  in  the 
soil.     In  this  connection  Gile  notes  that — 

Chlorosis  (sometimes  called  icterus,  bleaching,  or  Gelbsucht)  is  the  term 
applied  to  that  condition  assumed  by  the  leaves  of  plants  when  they  fail  to 
develop  the  normal  amount  of  chlorophyll,  or  green  coloring  matter,  i.  e.,  when 
they  are  yellowish  or  white  instead  of  a  normal  green.  Chlorosis,  then,  does  not 
denote  a  specific  disease,  but  merely  a  general  condition.  This  condition  of 
chlorosis,  however,  is  the  result  or  outward  sign  of  a  disease  or  disturbance  in 
the  physiology  of  the  plant.  To  say  that  a  plant  is  chlorotic  or  affected  with 
chlorosis  means  merely  that  its  leaves  are  lacking  in  chlorophyll;  but  the  chloro- 
sis may  have  resulted  from  a  bacterial  disease,  poor  drainage,  lack  of  nutriment, 
or  some  other  cause. 

Bleaching  was  found  to  occur  on  soils  very  high  in  calcium  car- 
bonate while  healthy  plants  were  found  on  a  soil  containing  1.14 
per  cent  calcium  carbonate  and  a  total  lime  content  of  1.92  per  cent. 
Manganese  is  not  associated  by  Gile  with  this  chlorosis  as  no  man- 
ganese is  reported  as  present  in  the  soils  or  in  the  plants.  Bleach- 
ing in  this  case  appeared  to  be  somewhat  different  from  the  yellowing 
of  pineapples  which  occurs  on  manganiferous  soils.  Although  a  few 
cases  of  yellowing  are  noted,  the  typical  appearance  described  is 
that  of  "waxy  white"  or  " ivory  white."  No  mention  is  made  of 
the  very  characteristic  red  fruit  which  appears  on  manganiferous 
soils.  The  application  of  stable  manure  was  found  to  be  ineffective 
on  these  calcareous  soils. 

In  this,  as  in  previous  cases  of  chlorosis  which  were  induced  by 
lack  of  iron  in  plants  growing  on  highly  calcareous  soils,  Gile  founcl 
that  the  plants  were  benefited  when  the  leaves  were  brushed  with 
iron  salts  in  solution,  but  that  the  treatment  was  impracticable  for 
Porto  Rican  conditions.     Gile  (Id,  p.  34)  states  that — 

It  is  very  doubtful  if  treatment  with  iron  salts  would  render  pineapple  growing 
on  calcareous  soils  commercially  successful,  as  the  repeated  treatments  with 
iron  would  be  expensive  and  the  crop  would  not  be  equal  to  that  secured  from 
soils  naturally  adapted  to  pineapples. 

STATUS   OF  THE  MANGANESE  PROBLEM   WHEN  THE  PRESENT 
INVESTIGATIONS   WERE  UNDERTAKEN. 

From  a  review  of  the  literature  on  manganese,  it  appears  that  the 
results  and  conclusions  concerning  the  effect  of  this  element  on  plants 
are  very  contradictory.  Manganese  is  commonly  thought  to  exert 
a  stimulating  action,  but  there  seems  to  be  no  positive  proof  that 
such  stimulation  is  due  primarily  to  manganese.  The  experiments 
in  soil  culture  are  so  contradictory  that  the  stimulative  effects  found 
may  be  considered  due  to  the  effect  of  the  anion,  usually  the  sul- 
phate, which  is  known  to  cause  decided  stimulation,  particularly  on 
alkaline  soils.  The  possibility  of  manganese  being  a  necessary  ele- 
ment is  sometimes  discussed  because  of  its  occurrence  in  the  ash  of 
plants.  Aluminum  also  is  found  in  the  ash  of  plants,  but  aluminum 
is  not  considered  a  necessary  component;  in  fact,  under  some  condi- 
tions there  is  ground  for  suspicion  that  aluminum  salts  are  toxic. 
Results  obtained  from  most  of  the  experiments  in  nutrient  solutions, 
intended  to  illustrate  the  stimulating  effect  of  manganese,  are  of 
very  doubtful  value  since  increase  in  height  of  a  plant  during  a  short 
period  of  growth  is  usually  the  only  measurement  used  to  determine 
stimulation.     The  conclusion  seems  to  be  fairly  general  among  most 


MANGANESE   CHLOROSIS   OF   PINEAPPLE.  7 

investigators,  however,  that  manganese  in  higher  concentrations 
causes  a  bleaching  or  yellowing  of  the  leaves  and  a  depression  in 
growth. 

In  connection  directly  with  the  manganese  problem  in  Hawaii, 
Kelley  (28,  29,  30,  31,  32),  as  already  mentioned,  had  made  a  very 
thorough  investigation  of  the  manganese  problem.  He  had  estab- 
lished the  correlation  between  yellowing  of  pineapples  and  an  abnor- 
mal amount  of  manganese  in  the  soil.  The  very  valuable  data 
obtained  by  him  in  his  extensive  series  of  soil  and  plant  analyses 
should  be  consulted  in  conjunction  with  this  publication  as  his 
investigations  are  complementary  to  the  writer's.  The  toxic  effects 
of  manganese  were  attributed  by  Kelley  to  modification  in  the 
osmotic  absorption  of  lime  and  magnesia. 

At  the  time  the  writer  attacked  the  manganese  problem,  the 
injurious  effects  of  manganese  on  plants  were  attributed  by  practi- 
cally all  scientific  investigators  to  an  indefinite  " toxic  effect"  and  to 
11  manganese  poisoning."  A  large  amount  of  literature  on  lime- 
induced  chlorosis  has  been  available  for  many  years,  and  it  has  been 
known  that  plants  on  highly  calcareous  soils  become  ehlorotic,  and 
that  spraying  with  solutions  of  iron  sulphate  overcame  this  chlorosis. 
No  proof,  however,  had  been  presented  to  show  that  the  indefinite 
"toxic  effects"  of  manganese  are  in  any  way  similar  to  lime-induced 
chlorosis,  nor  that  manganese  causes  a  deficiency  of  iron  in  the  plant 
nor  that  spraying  with  solution  of  iron  sulphate  will  cure  "  manganese 
poisoning."  In  Hawaii,  pineapple  plants  were  dying  on  hundreds 
of  acres  of  manganese  soil.  No  remedy  having  been  found  for  this 
condition,  except,  possibly,  heavy  applications  of  stable  manure, 
which  was  expensive,  only  temporarily  beneficial,  and  limited  in  supply, 
many  thousands  of  acres  have  been  abandoned  or  left  uncultivated. 
So  little  understood  was  the  real  nature  of  the  manganese  problem 
that  experiments  were  being  carried  on  with  coral  sand  on  the 
manganese  soils.  Had  the  "toxic  effect"  of  manganese  been 
known  to  be  due  to  a  depressed  assimilation  of  iron  by  the  plant, 
calcium  carbonate,  in  the  form  of  coral  sand,  would  not  have  been 
added  to  depress  the  assimilation  of  iron  still  further. 

THE  MANGANIFEROUS  SOILS  AND  THEIR  EFFECT  ON  PINEAPPLE 
AND  OTHER  PLANTS. 

COMPOSITION  OF  THE  MANGANIFEROUS  SOILS. 

The  chief  difference  in  chemical  composition  noticed  by  Kelley 
between  the  black  soils  where  ''pineapple  yellows"  occurred,  and 
the  normal  soils  where  the  plants  were  healthy,  was  in  the  high 
content  of  manganese  of  the  former.  Kelley  (32)  gives  the  composi- 
tion of  these  soils  in  the  accompanying  analyses. 


BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 
Table  1. — Composition  of  manganiferous  and  normal  soils  of  Oahu. 


Constituents. 


Insoluble  matter 

Potash  (KaO) .: 

Soda(Na20) 

Lime  (CaO) 

Magnesia  (MgO) 

Manganese  oxid  (Mn(304)-. 

Ferric  oxid  (Fe203) 

Alumina  (AI2O3) 

Phosphorus  pentoxid  (P2O5) 

Sulphur  trioxid  (SO3) 

Titanic  dioxid  (Ti02) 

Loss  on  ignition 

Total 

Nitrogen  (N) 


Manganiferous  soils. 


Soil. 
No. 


P.ct. 

33.  46 
.83 
.40 
1.39 
.55 
9.74 

19.65 

15.50 
.21 
.16 
.73 

17.73 


100.  35 
.39 


Sub- 
soil. 
No. 
10. 


P.  ct. 

36.06 
.74 
.42 
.86 
.43 
8.76 

21.51 

15.74 
.16 
.09 
1.09 

14.45 


100.31 
.23 


Soil. 
No. 
11. 


P.ct. 

39.02 
.78 
.36 
.64 
.41 
4.80 

18.24 

15.40 
.36 
.23 
.40 

19.71 


Sub- 
soil. 
No. 
12. 


P.ct. 

42.60 
.81 
.44 
.60 
.39 
3.50 

20.  52 

16.89 
.13 
.05 
.58 

13.  72 


100.35  1 100.  23 
.  45  !       .  19 


Soil. 
No. 
15. 


P.  ct. 

33.73 
.99 
.21 

.49 

.52 

4.01 

26.03 

15.  82 

.35 

.17 

.85 

16.68 


).  85 
.35 


Sub- 
soil. 
No. 
16. 


P.  ct. 

34.53 

1.07 

.38 

.37 

.41 

2.43 

26.85 

18.98 

.21 

.05 

1.58 

12.83 


Soil. 
No. 

27. 


P.ct. 

42.08 
.65 
.32 
.19 
.35 
4.14 

22.  05 

16.01 
.13 
.37 

0) 
14.02 


99.69  :  100.  31 
.20         .27 


ton      Soil- 

No"       No. 

28.         5L 


P.ct. 

42.78 
.64 
.37 
.21 
.28 
3.59 

21.36 

19.51 
.11 
.30 
(■) 

11.31 


P.ct. 

38.78 
.83 
.34 
.24 
.64 
4.32- 

20.40 

19.  35 
.11 
.29 

0) 

15.  29 


100.46    100.59 
:24 


Sub- 
soil. 
No. 

52. 


P.ct. 

39.74 

.76 

.47 

.26 

.49 

4.24 

25.  38 

16.14 

.14 

.28 

0) 

12.45 


100.35 
.13 


Constituents. 


Insoluble  matter 

Potash  (K2O) . 

Soda  (Na20) 

Lime  (CaO) 

Magnesia  (MgO) 

Manganese  oxid  (MmO-i).-- 

Ferric  oxid  (Fe203) 

Alumina  (AI2O3) 

Phosphorus  pentoxid  (P2O5) 

Sulphur  trioxid  (SO3)- 

Titanic  dioxid  (Ti02) 

Loss  on  ignition 

Total.. 

Nitrogen  (N) 


Normal  soils. 


Soil. 
No. 

7. 


Sub- 
soil. 

No. 


P.ct. 

40.89 
.51 
.21 
.51 
.37 
.22 

35.72 

3.58 

.07 

.09 

3.83 

14.22 


100.  22 


P.ct. 
39.25 


33.28 


.07 
2.74 
13.99 


100.  09 
.25 


Soil. 
No. 
13. 


Sub- 
soil. 
No. 
14. 


P.  ct.   \ 

46.  52 
.50 
.31 
.32 
.40 
.33 

24.37 

9.15 

.09 

.11 

2.20 

15.98 


P.  ct. 

46.  37 
.57 
.13 
.31 
.42 
.35 

24.49 

12.02 

.13 

.12 

2.05 

13.  17 


100.  28  i  100.  13 
.  38  I        .25 

! 


Soil. 

No. 
31. 


Sub- 
soil. 
No. 
32. 


P.  ct. 

41.73 
.53 
.20 
.22 
.36 
.22 

23.29 

16.02 
.08 
.46 

0) 

17.22 


100.33 
.29 


P.ct. 

37.16 
.57 
.37 
.15 
.30 
.39 

24.13 

20.87 
.12 
.33 
0) 

16.38 


100.77 
.20 


Soil. 
No. 
49. 


P.ct. 

42.36 
.65 
.46 
.23 
.47 
1.17 

20.36 

20.37 
.10 
.23 
0) 

13.22 


99.62 
.27 


Sub- 
soil. 
No. 
50. 


P.ct. 

39.82 
.48 
.20 
.12 
.44 
.36 

25.  87 

19.42 
.10 
.42 

(>) 

13.33 


100.56 
.14 


Soil. 

No. 
19. 


P.  ct. 

44.00 
.59 
.?9 
.24 
.42 
.16 

27.94 

11.91 
.04 
.11 
.28 

13.95 


99.93 
.29 


1  Titanium  was  not  separated  from  alumina. 

These  analyses  show  that  the  manganiferous  soils  are  well  supplied 
with  nitrogen,  phosphoric  acid,  and  potash,  usually  considered  the 
three  most  important  plant  foods,  and  that  they  even  surpass  the 
normal  soils  in  their  supply  of  these  constituents.  Kelley  showed 
that  the  black  soils  are  superior  to  the  average  soils  in  physical 
properties,  and  that  nitrification,  one  of  the  principal  bacteriological 
factors  affecting  soil  fertility,  takes  place  more  rapidly  in  the  man- 
ganiferous soils  than  in  the  nonmanganiferous  soils.  Comparative 
solubilities  in  water  and  dilute  organic  acids  showed  little  differences 
except  in  the  much  greater  quantities  of  the  manganese  which  were 
dissolved  from  the  black  soils. 

Table  2  gives  some  analyses  of  soils  on  which  yellowing  of  pine- 
apples occurred. 


MANGANESE    CHLOROSIS    OF   PINEAPPLE. 
Table  2. — Analyses  of  manganiferous  soils.1 


Constituents. 

Soil  laboratory  numbers. 

635 

636 

637 

638 

639 

640 

641 

Manganese  oxid  (M113O4) 

Insoluble  matter ..  ..    , 

Per  cent. 

0.31 

29.43 

.21 

.83 

.39 

.43 

15.  50 

30.79 

.51 

.36 

19.76 

1.74 

Per  cent. 
4.80 

39.  99 
.21 
.87 
.39 
.61 

13.23 

22.78 
.55 
.42 

15.63 
.62 

Per  cent. 
5.19 

38.28 
.34 
.56 
.42 
.57 

12.26 

25.  05 
.51 
.34 

15.71 
.72 

Per  cent. 
5.12 

39.28 
.33 
.62 
.44 
.47 

12.27 

24.62 
.50 
.32 

15.  50 

•H 

Per  cent. 
2.51 

39.79 
.38 
.92 
.35 
.43 

10.42 

25.70 
.56 
.48 

18.06 
.73 

Per  cent. 
5.58 

38.08 
.40 
.65 
.43 
.40 

10.95 

25.33 
.61 
.31 

16.89 
.53 

Per  cent. 

2.85 

39.63 

Potash  (K2O) 

.34 

Soda  (NaaO) 

Lime  (CaO) 

.60 

.36 

Magnesia  fllgO) . 

.51 

Ferric  oxid  (Fe203)    . 

13.44 

Alumina  (AI2O3) 

23.37 

Phosphorus  pent  oxid  (P2O5) 

Sulphur  trioxid  (SO3)---  - 

.53 
.36 

Volatile  matter 

17.23 

Titanic  dioxid  (TiO)     . 

.83 

1  These  soils  will  be  referred  to  later  in  the  text. 

These  analyses  are  similar  to  those  of  Keller  in  that  they  show 
a  high  content  of  manganese  where  the  yellowing  occurred,  with  the 
exception  of  soil  No.  635,  which  was  obtained  from  Kunia,  Oahu. 
The  plants  on  this  soil  were  yellow  and  produced  characteristic  red 
fruit.  This  soil,  according  to  the  analysis,  contained  only  0.31  per 
cent  of  manganese  calculated  as  the  mangano-manganic  oxid.  That 
this  manganese  is  actually  present  as  the  dioxid  will  be  shown,  while 
the  manganese  in  normal  soils  is  probably  in  the  silicate  form. 

FORM  IN  WHICH  MANGANESE  OCCURS  IN  THE  SOIL. 

Kelley,  in  his  analyses,  reported  the  manganese  calculated  as  the 
mangano-manganic  oxid  (Mn304),  but  concluded  from  his  investiga- 
tions that  at  least  part  of  the  manganese  is  present  as  higher  oxids, 
since  there  is  a  liberation  of  chlorin  gas  with  acids  and  a  change  in 
appearance  during  ignition. 

To  determine  the  form  in  which  manganese  was  present  in  the 
soil,  the  writer  distilled  the  samples  according  to  the  Bunsen  method 
for  available  oxygen  in  pyrolusite.  Table  3  compares  the  manganese 
dioxid,  calculated  from  these  results,  with  the  total  manganese  pres- 
ent, calculated  to  the  same  form. 

Table  3. — Comparison  of  total  manganese  with  manganese  dioxid  in  the  manganif- 
erous soils. 


Laboratory  soil  number. 

Total 

manganese 

dioxid  by 

official 

method. 

Manganese 

dioxid 

according  to 

the  Bunsen 

distillation 

method. 

Laboratory  soil  number. 

Total        Manganese 

official        the  Bunsen 
mShod       d^tmation 
method.    (    method 

635 

Per  cent. 
0.35 
5.48 
5.92 
5.86 

Per  cent. 
0.35 
4.85 
5.20 
5.15 

639 

Per  cent.        Per  cent. 
2.  86  ',                2.  66 

636 

640 

6  36                  K  fi7 

637 

641 

3.25 

1.92 

638 

Since  the  distillation  method  probably  gives  low  results  owing  to 
the  presence  of  organic  matter,  it  is  safe  to  conclude  that  nearly  all 
the  manganese  present  is  in  the  form  of  dioxid.     This  assumption  is 
86067— 24f 2 


10 


BULLETIN    52,    HAWAII   EXPERIMENT   STATION. 


based  on  the  fact  that  the  usual  manganese  ore  is  the  dioxid  (pyro- 
lusite),  and  that  solutions  of  manganese  in  the  carbonate  form"  in 
which  form  it  is  probable  that  the  manganese  is  leached  out  of  the 
original  lava,3  soon  precipitate  manganese  dioxid  because  of  their 
strong  hydrolysis  and  oxidation  by  the  air. 

IRON  IN  THE  MANGANIFEROUS  SOILS. 

Kelley  (32)  reported  the  presence  of  18.24  to  26.85  per  cent  of 
iron  as  ferric  oxid,  while  the  writer  found  a  variation  of  10.42  to  15.5 
per  cent  in  the  soil  samples  he  analyzed.  Hawaiian  soils  4  contain 
an  abundance  of  iron,  having  several  times  the  quantity  found  in 
ordinary  soils  of  the  mainland  or  pineapple  soils  of  other  countries. 

Kelley  (28)  determined  the  solubility  of  the  manganese  and  iron 
with  a  1  per  cent  solution  of  citric  acid.  In  this  determination  he 
gives  the  average  amount  of  iron  soluble  as  0.243  per  cent  ferric 
oxid,  or  about  8,500  pounds  per  acre-foot.  It  is  a  striking  peculiarity 
that,  notwithstanding  the  presence  in  these  manganiferous  soils  of 
an  immense  quantity  of  total  iron  and  of  citric  acid  soluble  iron,  the 
pineapple  plants  seemed  unable  to  assimilate  the  iron  but  showed  a 
pronounced  change  after  they  had  been  sprayed  with  30  to  40  pounds 
of  iron  sulphate  per  acre. 

The  failure  of  the  plants  to  absorb  iron,  notwithstanding  the  large 
amount  soluble  in  citric  acid,  seems  to  constitute  a  serious  criticism 
of  the  general  applicabilit}r  of  the  citric-acid  method  for  determining 
the  available  constituents  of  the  soil. 

REACTION  OF  THE  MANGANIFEROUS  SOILS. 

The  manganiferous  soils  when  tested  with  litmus  show  an  acid 
reaction.  Kelley  (28)  examined  a  large  number  of  these  black  soils 
and  found  most  of  them  slightly  acid  and  few  neutral. 

In  order  to  determine  more  exactly  the  acidity  of  these  manganese 
soils,  the  hydrogen-ion  concentrations  were  determined  electrically. 
The  hydrogen-ion  concentrations,  expressed  in  pH  values,  are  given 
in  Table  4. 

Table  4. — Hydrogen-ion  concentrations  (expressed  in  pH  values)  of  the  mangani- 
ferous soils. 


Laboratory  soil  number. 

Manganese 

oxid 
(M113O4). 

pH  value.   ; 

i 

Laboratory  soil  number. 

Manganese 

oxid          pH  value. 
(Mn304). 

9 

Per  cent. 
9.74 
4.80 
4.01 
4.14 
4.32 

t 

6.5 
6.4 
7.0  | 
5.7  j 

5.9 

636 __ 

Per  cent. 

4.  80                   6. 1 

11 

638                         

5. 12                   6. 3 

15 

639    .                       

2.  51                   6. 0 

27 

641 

2.85                   6.0 

51 

The  table  indicates  that  the  manganese  soils  in  nearly  every  instance 
are  fairly  acid,  since  soils  having  a  pH  value  lower  than  7,  the  neutral 
point  of  pure  water,  are  acid.  That  these  soils  are  lacking  in  car- 
bonate of  lime  is  proved  by  the  fact  that  calcareous  soils  would  have 

*  Lava  is  the  original  material  from  which  nearly  all  the  upland  soils  of  the  island  are  derived. 
4  Iron  is  one  of  the  most  abundant  elements  of  Hawaiian  soils. 


MANGANESE    CHLOROSIS    OF    PINEAPPLE. 


11 


an  alkaline  reaction  and  a  pH  value  approximately  8.2-8.4  (that  of 
carbonate  of  lime  in  water). 

AMOUNT  AND  FORM  OF  LIME  IN  THE  MANGANIFEROUS  SOILS. 

The  amount  of  lime  that  is  contained  in  manganiferous  soils  is  of 
interest  in  connection  with  the  reaction  of  these  soils.  Kelley 
reported  manganiferous  soils  containing  as  low  as  0.19  and  0.24  per 
cent  of  lime,  and  his  iigures  average  about  0.05  per  cent  of  lime. 
(See  Table  1.)  Soils  analyzed  by  the  writer  .averaged  about  0.4 
per  cent  of  lime.     (See  Table  2.) 

An  attempt  was  made  to  determine  the  presence  of  carbonate-  in 
the  manganiferous  soils  by  the  methods  of  Maclntire  and  Willis 
(34,  35)  of  treating  the  soils  with  1-15  H3P04,  and  by  their  later 
method  with  1-15  HC1.     Table  5  gives  the  results. 

Table  5. — Carbon  dioxid  content   of  the    manganiferous    soils    by    the    method    of 
•  Maclntire  and  Willis. 


Laboratory  soil  number. 

Carbon          Carbon 

,  dioxid  (1/15  dioxid  (1/15 

H3PO4).            HC1). 

Laborat 

ory 

soil 

number. 

Carbon 

dioxid  (1 ,15 

EUPO4). 

Carbon 

dioxid  (1  15 

HC1). 

635. 

636 

Per  cent. 

0.03 

.04 

.02 

.03 

Per  cent. 

0.04 

.07 

.06 

.06 

639 

640 

641 

Percent. 

0.04 

.03 

•       .  03 

Per  cent. 
0.03 
.05 

637 

638 

.06 

The  quantity  of  carbon  dioxid  found  in  these  soils  was  negligible 
and  indicated  the  practical  absence  of  carbonates,  as  soils  that  are 
known  to  be  free  from  carbon  dioxid  produce  considerable  amounts 
of  CO,  owing  to  the  action  of  acids  on  the  soil  organic  matter.  The 
values  which  were  found  for  the  hydrogen-ion  concentrations  of  these 
soils  proved  the  absence  from  them  of  calcium  carbonate.  The 
small  quantity  of  lime  in  the  soils  is,  therefore,  probably  present  in 
the  form  of  silicate  and  not  as  carbonate.  Some  of  it  may  be  present 
as  a  mangariite,  as  James  (23)  suggests.  It  will  be  shown  later  that 
the  injurious  effects  of  the  manganiferous  soils  are  due  to  deficiencies 
of  iron  in  the  plant  and  not  to  toxic  effects  of  calcium  manganite,  as 
James  further  suggests. 

EFFECTS  OF  MANGANESE  ON  RICE. 

It  has  already  been  explained  that  the  toxic  effects  of  manganif- 
erous soils  on  pineapple  plants  are  characterized  by  yellowing  of  the 
leaves,  cracking  open  and  decaying  of  immature  fruit,  which  is 
stunted  and  red  or  pink  instead  of  normal  size  and  green,  and  by  a 
general  unhealthy  appearance  of  the  plants.  The  injurious  effects 
of  manganese  are  verv  completelv  described  by  Wilcox  and  Kellev 
(46)  and  by  Kelley  {28,  29,  30.  31,  3.2). 


6  Constituents  other  than  lime  do  not  appear  of  significance  since  they  show  little  variation  from  the 
normal. 


12 


BULLETIN    52,    HAWAII   EXPERIMENT    STATION. 


Growth  of  Rice  in  Nutrient  Solutions. 

In  order  to  investigate  the  influence  of  manganese  more  fully  and 
without  the  complication  of  soil  phenomena,  various  experiments 
wore  conducted  in  nutrient  solutions  with  the  addition  of  manganese 
sulphate  and  manganese  dioxid.  Rice,  which  is  similar  to  the  pine- 
apple in  its  susceptibility  to  chlorosis,  was  used  in  these  experiments 
because  it  is  more  convenient  of  culture  in  nutrient  solutions  and 
furnishes  results  more  quickly  than  the  pineapple  plant. 

Experiment  I. — This  experiment  was  divided  into  two  series  of 
nine  tests  each,  using  the  nutrient  solutions  shown  in  Table  6. 

Table  6. — Nutrient  solutions  used. 


Series  I.— Loew  and  Sawa's  (-33)  nutri- 
ent solution. 


Calcium  nitrate 

Magnesium  sulphate 

Potassium  nitrate 

Monopotassium  phosphate 

Ammonium  sulphate 

Ferrous  sulphate 


Quantity. 


Series  II.— Gile  and    Carrero's    (17) 
acid  nutrient  solution. 


Per  cent. 
0.04 
.01 
.03 
.02 
.01 
.01 


Weight. 


Grams. 

Potassium  nitrate... 0. 1017 

Monobasic  potassium  phosphate .  0714 

Sodium  nitrate .  2143 

Sodium  sulphate .0315 

Calcium  chlorid .  05 

Magnesium  chlorid . .05 

Ferric  chlorid .0041 

Sulphuric  acid c.c.  X/m__  .  5 

Distilled  water c.c.  1.000 


The  manganese  dioxid  used  in  all  the  experiments  was  prepared  by 
Merck  and  marked  "artificial,"  and  "pure,"  and  contained  about 
90  per  cent  MnO,.  Ten  grams  of  this  manganese  dioxid  in  200 
cubic  centimeters  of  pure  water  gave,  on  18  and  42  hours'  contact, 
a  pH  value  of  about  6.6,  or  a  faintly  acid  reaction.  Coral  sand  and 
calcium  carbonate  under  the  same  conditions  gave  a  pH  value  of 
about  8.4  or  a  distinctly  alkaline  reaction. 

Rice  seedlings  were  germinated  in  distilled  water  and  transferred 
to  the  various  nutrient  solutions  when  the  plumules  were  about 
2  inches  long.  Four  plants  each  were  grown  in  large  flasks.  Dupli- 
cate tests  of  each  trial  were  made.  Transpired  water  was  replaced 
with  distilled  water  daily  and  the  solutions  were  changed  every 
fourth  day.  The  solutions  were  freshly  made  18  hours  before  chang- 
ing and  the  flasks  and  roots  were  rinsed  with  a  little  of  the  fresh 
solution  when  the  changes  were  made.  The  plants  were  grown  for 
40  days. 

The  plants  were  harvested  on  the  fortieth  day  and  the  green  and 
dry  weights  of  the  stalks  and  leaves  and  of  the  roots  were  determined. 
The  results  are  given  in  Tables  7  and  8. 


MANGANESE    CHLOROSIS    OF    PINEAPPLE. 


13 


Table  7. — Weight  and  condition  of  rice  grown  in  Loew  and  Sawa's  nutrient  solution 
to  which  manganous  sulphate,  manganese  dioxid,  and  calcium  carbonate  were 
added. 


ries. 


Culture  solutions  with  amount  Flask 
of  added  material  per  liter.       No. 


Mn    from 
Fe  omitted, 
gm.     Fe    from 
gm. 


Mn 


Check;    sol.+0.037   gm.    Fe 

from  FeS04. 
Sol. +0.037    gm.     Fe    from 

FeSOH-0.072     gm.     Mn  | 

from  MnS04. 
Sol. +0.072    gm, 

MnS04 
Sol.+0.U3 

FeSO  4+0.036 

from  MnS04. 
Sol. +0.037     gm 

FeSO4+0.018 

from  MnS04. 
Sol. +0.037     gm 

FeSO4+0.004 

from  MnS04. 
Sol. +0.037    gm.     Fe    from 

FeSO4+0.4  gm.  Mn02. 
Sol. +0.037    gm.     Fe    from 

FeSO4+0.4     gm.     MnO* 

+0.4  gm.  CaC03. 
Sol. +0.037    gm.     Fe    from 

FeSO4+0.4gm.  CaC03. 


Fe 
gm. 

Fe 
gm. 


from 
Mn 


from 
Mn 


Green 


Oven- 


weight  A4ght 

of 

stalks 

and 


of 

stalks 

and 


leaves. 


leaves. 


Grams.    Grams. 

2.  86         0.  58 

3.  70  .  66 


3.04 
3.59 

2.66 
2.67 

3.44 
4.15 

4.63 
4.60 

4.59 
4.58 

5.42 
6.74 


.48 
.48 

.04 
.05 

.58 
.59 


,61 


Oven- 
dry 
weight 

of 
roots. 


Grams. 
0.17 
.21 

.14 
.15 

.03 
.04 

.18 
.19 


Average  oven- 
dry  weight. 


Sta],ks     Whole 
leaavl     *■*■ 


Grams.    Grams. 


0.62 

0.81 

.48 

.63 

.05 

.08 

.59 

.77 

.54 

.75 

.67 

.80 

.84 

1.08 

.73 

.96 

.98 


Condition  of  plant 


j-Green;  healthy. 

{Green;  older  leaves 
spotted  with 
brown. 

JDead. 

{Green;  older  leaves 
spotted  with 
brown. 

>Green;  healthy. 


|  Do. 

}  Do. 

}  Do. 

}  Do. 


Table  8. — Weight  and  condition  of  rice  grown  in  Gile  and  Carrero's  nutrient  solu- 
tion to  which  manganous  sulphate,  manganese  dioxid,  and  calcium  carbonate  were 
added. 


Se- 


Culture  solutions  with  amount  Flask 
of  added  material  per  liter.       No 


Cheek;  sol. +0.0014  gm.  Fe 

from  FeCh. 
Sol. +0.0014    gm.    Fe    from 

FeCl3+0.072       gm.    Mn 

from  MnSOi. 
Sol. +0.072    gm.    Mn    from 

MnSO«;  Fe  omitted. 
Sol. +0.0014    gm.    Fe 

FeCl3+0.036      gm. 

from  MnS04. 
Sol. +0.0014    gm.    Fe 

FeCh+0.018      gm. 

from  MnS04. 
Sol. +0.0014    gm.    Fe 

FeCls+0.004      gm. 

from  MnS04. 

Sol. +0.0014  gm.  Fe  from 
FeCh+0.4  gm.  MnOi. 

Sol. +0.0014  gm.  Fe  from 
FeCh+0.4  gm.  Mn  from 
MnSO4+0.4gm.  CaCOs. 

SoL+0.0014    gm.    Fe    from 
FeCh+O.l  gm. 
CaC03. 


from 
Mn 


from 
Mn 


from 
Mn 


*>$*\  weight 


Grams. 
3.01 
2.71 

.20 
.25 

.13 
.07 

.65 


1.11 
.58 


2.16 
1.08 


Grams. 
0.52 


Oven- 
dry 

weight 

of 
roots. 


Grams. 

0.23 

.19 

.04 
.04 

.04 
.04 

.05 

.07 

.07 
.04 

.13 

.08 

.04 
.04 

.04 
.05 

.04 
.05 


Average  oven- 
dry  weight. 


Stalks 

and 
leaves. 


Grams. 


0.49 


Whole 

plant. 


Condition  of  plant 


Grams. 


0.70 


.21 


22  |. 


us 


|Green;  healthy. 

Leaves  shriveled; 
brown;  nearly 
dead. 

•Dead. 

Leaves  brown 
spotted  with 
dark  brown. 

Leaves  yellow 
and  brownish. 

Lower  leaves 

spotted  with 

brown. 
X  e  a  r  1  y  d  e  a  d  ; 

light  brownish 

white  color. 
Bleaehed:yellow 

ish- white; 

stunted. 

Do. 


14 


BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 


With  Loew  and  Sawa's  nutrient  solution,  manganous  sulphate  did 
not  cause  chlorosis  but  a  decrease  in  the  dry  weights  of  the  plants, 
except  in  the  smallest  amount  used.  On  the  other  hand,  manganese 
dioxid  and  calcium  carbonate,  singly  and  in  combination,  caused  a 
tremendous  increase  in  the  growth  of  the  plants.  Evidently,  then, 
this  solution  contained  an  excessive  amount  of  iron,  and  the  increase 
in  growth  was  due  to  manganese  dioxid  and  calcium  carbonate 
depressing  the  assimilation  of  some  of  this  harmful  iron.  This  nutri- 
ent solution  is  the  one  with  which  Loew  and  Sawa  obtained  results 
which  they  claimed  proved  the  supposedly  stimulating  effect  of 
manganese.  The  stimulating  effect  of  manganese  in  this  nutrient 
solution  is  doubtless  due  to  its  depressing  effect  on  the  assimilation 
of  the  excessive  amounts  of  iron  in  the  solution. 

With  Gile  and  Carrero's  acid  nutrient  solution,  an  amount  as 
small  as  4  milligrams  per  liter  of  manganese  from  manganous  sulphate 
(0.001  per  cent  of  manganous  sulphate)  was  sufficient  to  cause  brown 
spotting  of  the  leaves  and  a  decided  decrease  in  rate  of  growth. 
Practically  no  growth  was  made  in  the  presence  of  manganese 
dioxid  or  calcium  carbonate  and  the  plants  were  strongly  chlorotic. 
The  greatly  different  effects  of  manganese  in  these  two  nutrient 
solutions  seemed  to  be  due  either  to  the  form  or  to  the  amounts  of 
iron  supplied.  A  second  experiment  was  therefore  undertaken  in 
which  different  forms  of  iron  were  used  in  the  same  solution. 

Experiment  II. — In  order  to  obtain  results  comparable  with  those 
recorded  by  Gile  and  Carrero  (18),  it  was  decided  to  use  their  neutral 
nutrient  solution  in  all  the  later  experiments.  This  solution  had  the 
composition  shown  in  Table  9. 

Table  9. — Gile  and  Carrero's  neutral  nutrient  solution. 


Composition. 

Weight. 

Composition. 

Weight. 

Grams. 
10.71 
3.57 
3.57 
21.43 

Sodium  sulphate 

Grams. 
3.15 

Monobasic  potassium  phosphate 

C  alcium  chlorid 

2.00 

Magnesium  chlorid 

2.00 

Distilled  water 

100,000 

This  experiment  was  similar  to  Experiment  I.  Twelve  tests  were 
made. 

On  the  fortieth  day  the  plants  were  harvested  and  the  weights 
determined.     The  results  are  given  in  Table  10. 


MANGANESE   CHLOROSIS   OF   PINEAPPLE. 


15 


Table  10. — Comparative  weights  of  rice  plants  which  were  grown  in  nutrient  solu- 
tions containing  manganous  sulphate  and  manganese  dioxid  solutions,  to  which 
iron  as  ferrous  sulphate,  ferric  chlorid,  and  ferric  citrate  was  added. 


Se- 
ries. 


Culture  solutions  with 

amount  of  added  material 

per  liter. 


Check;  sol. +0.008    gm 

from  FeS04. 
Sol. +0.008    gm. 

FeSO4+0.072 

from  MnS04. 
Sol. +0.008    gm. 

FeSC-4+0.007 

from  MnS04. 


Fe 
gm. 

Fe 

gm. 


Fe 


from 
Mn 


from 
Mn 


Flask 
No. 


Sol. +0.008    gm.     Fe    from 
FeSO4+0.4  gm.  Mn02. 


Sol.+0.008 
FeCl3. 


gm.    Fe 


from    ' 
1 


Ba 

B, 

C 
C2 

C3 


Sol. +0.008    gm.    Fe    from 
FeCls+0.007  gm.  MnS04. 


Fe    from 
MnO,. 

Fe    from 


Fe 


Sol. +0.008    gm. 
FeCh+0.4  gm 

Sol. +0.008    gm. 

Fe2(C6H507)2. 
Sol. +0.008    gm. 

Fe2(C6H5O-)j+0.072 

Mn  from  MnS04. 
Sol. +0.008    gm.     Fe 

Fe2(C6H5O7)2+0.007 

Mnfrom  MnS04. 

Sol. +0.008 gm.  Fe2  (C6H507)2 
+0.4  gm.  Mn02. 


from 
gm. 

from 
gm. 


Bj     Sol.+O.OOS    gm.     Fe    from  j    11 
FeCh+0.072  gm.  MnS04.  \    12 


™fht    wSt 
Ieaves-    lelvl 


Grams, 
5.77 
6.01 

.80 
.72 

3.18 
2.38 


5.04 
4.66 

.23 

.27 

1.91 
1.42 

.15 
.20 

3.40 
4.94 

.11 
.08 

.25 
.29 


Grams. 
1.04 
1.03 

.20 
.20 

.65 


.07 


23  I        .49 

24  |        .49 


.87 
.85 


.38 

.04 
.06 

.56 
.79 

.04 
.03 

.06 


.10 
.12 


Oven- 
dry 
weight 

of 
roots. 


Grams. 

0.39 

.37 

.07 
.06 

.22 
'    .19 

.04 
.05 

.31 
.25 

.04 
.04 

.15 
.14 

.04 
.04 

.20 
.31 

.04 
.04 

.04 
.04 


05 


Average  oven- 
dry  weight. 


SandS    Whole 
lelves.    Plant- 


Grams.   Grams. 


1.04 

1.42 

.20 

.27 

.61 

.81 

.07 

.11 

.86 

1.14 

.08 

.12 

.42 

.57 

.05 

.09 

.68 

.93 

.04 

.08 

.06 

.10 

.11 

.17 

Condition  of  plants , 


Green;  healthy. 

Stunted;  light-col- 
ored, spotted 
with  brown. 


\Somewhat     stunt- 
81  /    ed;  light-colored. 

"Very  stunted;  yel- 
low and  bleached; 
spotted  with 
brown. 

Green;  healthy. 

Extremely  stunt- 
ed; leaves  with- 
ered; practically 
dead. 

IStunted;  light-col- 

/    ored. 

ery  stunted  ; 
leaves  almost 
white. 


[Green;  healthy. 

W  i  t  h  e  r  e  d    and 
dead. 

Very  pale  greenish- 
yellow;  leaves 
withered. 
Leaves  yellow  , 
spotted  with 
brown. 


The  form  in  which  iron  was  supplied  did  not  seem  to  change  the 
effects  of  the  manganese.  As  small  an  amount  as  7  milligrams  per 
liter  of  manganese  as  manganous  sulphate  (0.002  per  cent  of  man- 
ganous sulphate)  caused  chlorosis  and  a  very  striking  decrease  in 
weight  of  plants.  Manganese  dioxid  produced  a  similar  effect.  Fer- 
rous sulphate  appeared  to  be  the  best  source  of  iron  supply,  with 
ferric  chlorid  next,  and  ferric  citrate  last. 

Experiment  III. — It  was  decided  to  investigate  more  thoroughly 
the  effects  of  varying  amounts  of  iron,  because  the  effects  of  man- 
ganese seemed  to  depend  largely  on  the  iron  content  in  the  nutrient 
solution.  Tests  with  nutrient  solution  which  had  been  used  in  Ex- 
periment II  were  repeated.  Two  plants  were  grown  in  each  flask,  two 
flasks  were  taken  as  a  unit,  and  the  units  were  triplicated  for  each 
variable.     Eighteen  tests  were  made. 

The  leaves  of  the  plants  in  series  A4,  B41  and  C4  were  dipped  in  a 
0.5  per  cent  solution  of  ferrous  sulphate  several  hours  before  the 
nutrient  solutions  were  changed  so  as  to  minimize  chances  of  the 
dipping  solution  getting  into  the  nutrient  solution. 

Representative  plants  of  each  trial  were  photographed  on  the  for- 
tieth day  just  before  harvesting.  The  weights  of  the  harvested  plants 
are  given  in  Table  11  and  graphically  in  Figure  1. 


lb 


BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 


Table  11. — Comparative  weights  of  rice  plants  which  were  grown  in  manganous 
sulphate  and  manganese  dioxid  solutions  to  which  were  added  various  amounts 
of  iron  as  ferrous  sulphate. 


Se- 
ries. 

Culture    solutions   with 
amount   of  added  ma- 
terial per  liter. 

Flask 
No. 

Green 
weight 

of 

stalks 

and 

leaves. 

Oven- 
dry 
weight 

Oven- 
dry 
weight 

of 
roots. 

Average  oven- 
dry  weight. 

1 

of 

stalks 

and 

leaves. 

Stalks 

and 

leaves. 

Whole 
plant. 

Condition  of  plants. 

A, 

Sol. +0.005  gm.  Fe  from 
FeSo4. 

Sol. +0.005  gm.  Fe  from 
FeSO4+0.4  gm.  Mn02. 

Sol. +0.005  gm.  Fe  from 

FeS O4+O.OI8  gm.   Mn 
from  MnS04. 

Sol. +0.005  gm.  Fe  from 
FeSOi+0.4  gm.  Mn02; 
leaves  dipped  in  0.5  per 
cent  FeSO\  solution. 

Sol. +0.010  gm.  Fe  from 
FeS04. 

Sol. +0.010  gm.  Fe  from 
FeSO4+0.400gm.  Mn02. 

Sol. +0.010  gm.  Fe  from 
FeSO4+0.018    gm.    Mn 

from  MnS04. 
Sol. +0.010  gm.  Fe  from 

FeSCn— 0.4  gm.  MnG2; 

leaves  dipped  in  0.5  per 

cent  FeS04  solution. 

Sol. +0.020  gm.  Fe  from 
FeS04. 

f    !"2 
3-4 

I    5-6 

1     7-8 
\     9-10 
I  11-12 

(  13-14 
\  15-16 
I  17-18 

I   19-20 
\  21-22 

Grams. 
15.05 
15.  48 
15.  71 

.29 
.29 
.32 

.67 
.62 
.64 

2.15 
2.  15 

Grams. 
2.41 
2.53 

2.48 

.08 
.07 
.08 

.16 
.14 
.15 

.43 
.42 
.44 

2.56 
2.56 
2.65 

.10 
.10 
.09 

1.28 
1.33 
1.29 

.37 

Grams. 
1.05 
1.07 
1.00 

.06 
.06 
.06 

.06 
.06 
.06 

.17 
.22 
.18 

1.06 

Grams. 
'"2.4 

Grams. 
""%.l\~ 

•Fine;  green. 

Leaves  white,  spot- 

A  2 

1     ted  with  brown; 

A3 

.08 

.14 

shriveled        and 
stunted:  dead. 
Light       yellowish- 
green,       spotted 

with      brown; 

A  4 

.15 

.21 

older  leaves  very 
chlorotic,    shriv- 
eled,and  stunted. 
Great      improve- 
ment    over     Aa; 
light  green:  spot- 

ted    with     dark 
green  where  iron 
penetrated:     few 
brown   spots   on 
leave?. 

j  23-24           2.17 

15.21 
\  27-28         15.17 
I  29-30         15.47 

f  31-32             . 32 

.43 

.62 

Bi 

1.07 

/Fine:  green. 

1.01 

.06 
.07 

.05 

.39 
.41 
.40 

.13 
.  12 

2.59 

3.64 

(Bleached;    spotted 

J     with      brown; 

B2 

\  33-34 
(  35-36 

37-38 
39-40 
41-42 

43-44 

•  45-46 
)  47-48 

1  49-50 
{  51-52 
I  53-54 

f  55-56 

.35 
.27 

5.91 
5.  95 
6.13 

1.  55 

B3 

.10 

.16 

slightly       better 
I     than  A2. 
1  Light  green  spotted 

/    with  brown;  still 
1     stunted. 

|  About  same  as  A4; 
>    decided  improve- 

Bi 

1.30 

1.70 

1.  50           .  37 
1.67           .40 

13.69          2.26 
13.  64          Q.  2i 

.16 
.90 

.99 

.16 
.19 

.38 

.52 

1     ment  over  B2. 

Ci 



>Fine;  green. 

2.25 
2.76 
2.51 

6.93 
6.61 

2.48 
2.63 
2.66 

13.56 
12.78 
13.24 
12.44 
12.45 
12.23 
11.70 

2.51 

.50 
.60 
.56 

.1.43 
1.48 
1.40 

.58 

.62 

- 

2.41 
2.17 
2.30 
2.33 
2.30 
2.30 
1.95 
2.03 
2.06 
1.51 
1.48 
1.41 
1.73 
1.69 
1.  73 
1.38 
1.42 
1.40 

2.33 

3.23 

Somewhatstunted; 
light  green  spot- 
ted with  some 
brown. 

Dark  green;  infe- 
rior in  size  to  O; 

C2 

Sol. +0.020  gm.  Fe  from    1 





C3 

Fe.^Oi— 0.4  gm.  Mn02. 

Sol. +0.020  gm.  Fe  from 
FeSO4+0.018  gm.  Mn 
from  MnSO*. 

• 
Sol. +0.020  gm.  Fe  from 

I  59-60 

f  61-62 

\  63-64 
I  65-66 

)   67-68 
\  69-70 
}  71-72 

f  73-74 
\  7.5-76 
I  77-78 
f  79-80 
\  81-82 
[  83-84 
f  85-86 

.18 

.41 

.48 
.47 

.20 
.23 
.26 

.55 

.73 

.   

older      leaves 

ct 

1.44 

1.89 

shriveled,       but 
showed    scarcely 
a  trace  of  brown. 
About  same  as  B<; 
dark  greei 
where  iron  1  ene- 
trated. 

j-i -.-'j;— u.4  gm.  mduj; 
leaves  dipped  in  0.5  per 
cent  FeSO*  solution. 

'"".hi 

""."84" 

Di     Sol. +0.040  gm.  Fe  from 

.79 
.85 

| 

.70 
.71 
.64 
.58 

.85 
.86 

.84 
.59 
.62 

.62 

>Dark  green. 

FeS04. 

2.29 

3.09  I 

Do     Sol. +0.040  gm.  Fe  from 

f        Do. 

F^O4+0.4  gm.  MnG2. 

D3     Sol. +0.040  gm.  Fe  from 
FeSO«+0.018  gm.   Mn 
from  MnSO«. 

2.31 

3.04 

\  87-88         12.06 
1  89-90     1     12. 05 
91-92            7.  *y 
\  93-94 
I  95-96           7.  2S 

\  99-100         9.44 
[101-102         9.  77 
103-104 

•{105-106       7  sa 

\       Do. 

2.01 

2.71 

Ei       Sol. +0.080  gm.  Fe  from 

[        Do. 

FeS04. 

1.47 

2.08 

E-       Sol.— 0.080  gm.  Fe  from 

\        Do. 

F.  SO4+O.4  gm.  Mn02. 
E        Sol.— 0.080  gm.  Fe  from 

F^n.-Ufimfc    ptti      \Tn 

1.72 

2.57 

1        Do. 

from  MnS04. 

1107-108 

" 

1.40 

2.01 

MAXGANESE    CHLOROSIS   OF   PINEAPPLE. 


17 


The  text  to  Figure  1  and  Table  11  show  that  chlorosis  and  severe 
depression  in  growth  were  caused  by  manganese  dioxid,  with  5,  10\ 
or  20  milligrams  per  liter  of  iron  supplied  from  ferrous  sulphate,  and 
also  by  18  milligrams  per  liter  of  manganese  from  manganous  sulphate 
(0.005  per  cent  manganous  sulphate).  When  the  leaves  were  dipped 
in  iron  solution  chlorosis  was  overcome,  but  full  normal  growth  was 


&  SO        20  40  80 

Fig.  1.— (Results  of  Experiment  III.)     Effect  of  manganous  sulphate   and  manganese  dioxid  on  the 
growth  of  rice  in  nutrient  solutions  with  various  amounts  of  iron  supplied  from  ferrous  sulphate. 

not  induced.  The  writer  found  it  very  difficult  to  supply  iron  to  the 
leaves  of  the  rice  plant  because  they  seem  adapted  for  shedding  solu- 
tions. Where  the  iron  penetrated  the  leaves,  very  dark  green  spots 
appeared.  When  the  amount  of  iron  in  the  solution  was  increased 
excessively,  the  chlorotic  effect  of  manganese  was  completely  over- 
come. In  fact,  apparently,  because  of  its  removal  of  some  of  the 
excessive  iron,  manganese  dioxid  gave  slightly  better  results  than 
the  check. 

86067— 2-it 3 


18 


BULLETIN    52,    HAWAII   EXPERIMENT   STATION. 


Experiment  IV. — Experiment  III  was  repeated,  using  a  different 
form  of  iron.  The  different  variables  were  the  same  as  in  Experiment 
III  except  that  ferric  chlorid  was  the  source  of  iron,  and  the  plants 


<s  /o      20  40  30 

Fig.  2.— (Results  of  Experiment  IV.)    Effect  of  manganous  sulphate  and  manganese  dioxid  on  the 
growth  of  rice  in  nutrient  solutions  supplied  with  various  amounts  of  iron  from  ferric  chlorid. 

in  series  A4,  B4,  and  C4  were  dipped  in  a  0.5  per  cent  solution  of  ferric 
chlorid  instead  of  ferrous  sulphate. 

The  weights  of  the  plants  on  the  fortieth  day  are  given  in  Table  12 
and  graphically  in  Figure  2. 


MANGANESE    CHLOROSIS    OF    PINEAPPLE. 


,19 


Table  12. — Comparative  weights  of  rice  plants  which  were  grown  in  manganous 
sulphate  and  manganese  dioxid  solutions  to  which  were  added  various  amounts 
of  iron  as  ferric  chlorid.  . 


Culture  solutions  with 
amount  of  added  ma- 
terial per  liter. 


Flask 
No. 


Green 
weight 

of 

stalks 

and 

leaves. 


Oven- 
dry 

weight 
of 

stalks 
and 

leaves. 


Oven- 
dry 
weight 

of 
roots. 


Average  oven- 
dry  weight. 


leaves.     Plant- 


Condition  of  plants. 


Sol. +0.005  gm. 
FeCls 


D, 


Fe  from 


Sol.  +0.005  gm.  Fe  from 
FeCh+0.4  gm.  Mn02 


Sol. +0.005  gm.  Fe  from 
FeCh+0.018  gm.  Mn 
from  MnSO<. 


f    1_    2 
\    3-    4 

I    5-    6 

•      I  11-  12 

f  13-  14 
\  15-  16 

I  17-  IS 


Sol. +0.005  gm.  Fe  from  1  ia_  ™ 

FeCl3+0.4  gm.  M11O4;  I  ^T  g 

leaves  dipped  in  0.5  per  (  ™    %. 

cent  FeCls  solution.  J  a~  A 


Sol. +0.010  gm. 
FeCh. 


Fe  from 


Sol. +0.010  gm.  Fe  from 
FeCl3+0.4  gm.  Mn02. 

Sol. +0.010  gm.  Fe  from 
FeCl3+0.01S  gm.  Mn 
from  MnS04. 


Sol. +0.010  gm.  Fe  from  }  ,,    *. 

FeCl3;  leaves  dipped  in  I  jt    it  ?™ 

0.5  per  cent  FeCl3  solu-  f  *2~  !£  £  'A 

tion.  *'    *8  °-  °° 


2> 
30 
31-  32 
<[  33-  34 
[  35-  36 
(  37-  38 
\  39-  40 
:  I  41-  42 


Grams. 
20.50 
20.34 
19.89 

.25 
.28 

.28 

1.15 
1.14 
1.16 


.85 
.93 
.92 


20.52 
20.48 
19.97 
2.37 
1.87  I 
2.16  | 
3.92  | 
3.79 
4.13 


Sol. +0.020  gm.  Fe  from 
FeClj. 

Sol.+0.02C  gm.  Fe  from 
0.4  gm.  Mn02. 

Sol. +0.020  gm.  Fe  from 
FeCl3+0.01S  gm.  Mn 
from  MnSO<. 

Sol. +0.020  gm.  Fe  from 
FeCh;  leaves  dipped  in 
0.5  per  cent  FeCU  solu- 
tion. 


Sol. +0.040  gm.  Fe  from 
FeCU. 


Sol. +0.040  gm.  Fe  from 
FeCh+0.4  gm.  Mn02. 

Sol. +0.040  gm.  Fe  from 
FeCh-i-0.  01s  gm.  Mn 
from  MnSOi. 


Sol. +0.080  gm.  Fe  from 
FeCl3. 


Sol. +0.080  gm.  Fe  from 
FeCh+0.4  gm.  MnOj. 

Sol. +0.080  gm.  Fe  from 
FeCh+0.018  gm.  Mn 
from  MnS04. 


f  49- 

1  51" 
l  53- 

(55- 
l  59- 

f  61- 

\  63- 
l  65- 

67- 
Vh 
71- 


79-  80 
81-  82 
83-  84 
85-  86 
87-  88 
89-  90 

91-  92 
93-  94 
95-  96 

97-  98 
99-100 
101-102 
103-104 
105-106 
107-108 


15.58 
16.83 
15.38  I 


Grams. 
3.33 
3.39 
3.33 

.09 
.09 
.09 

.30 
.30 
.31 


3.60 
3.46 
.50 
.43 
.48 
.92 
.91 
.95 

1.16 
1.13 
1.11 

2.60 
2.89 
2.61 


56 
5S 
60 

10.72 

10.70 

1.17 

1.83 
1.87 
2.00 

62 
64 
66 

6.56 
7.16 
6.26 

1.56 
1.53 
1.43 

9.58 
10.15 
10.70 


3.17 
3.58 
3.06 


4.58 
4.96 
4.70 
2.98 
2.85 
2.96 

.42 
.67 
.42 

1.16 
1.18 
1.30 
.66 
.64 
.59 


1.83 
1.91 
1.86 


.91 

.78 


1.09 
1.18 
1.12 
.75 
.67 
.72 

.14 
.20 
.12 

.30 
.31 
.36 
.19 
.18 
.17 


Grams. 
1.30 
1.34 
1.30 

.06 
.06 


.08 
.08 
.08 


.11 
.11 
.10 


1.34 
1.23 
1.16 
.16 
.14 
.18 
.20 
.17 
.21 

.45 
.46 
.44 

.78 
.94 

.78 

.61 
.65 
.67 

.38 


Grams.    Grams. 


3.35 


09 


30 


.24 


3.57 


.47 


93 


1.13 


2.70 


1.90 


^4 


1.13 


.15 


38 


35 


4.81 


-,3 


IVery  fine;  green; 
healthy. 

'(Bleached  white; 
I  withered;  very 
j  stunted;  practi- 
l    cally  dead. 

{Very  stunted;  yel- 
lowish; lower 
leaves  withered 
and  spotted  with 
brown. 
Decided  improve- 
ment over  A2; 
yellowish-green, 
showing  dark 
green  spots 
where  iron  pene- 
trated. 

Green;  healthy. 

Stunted;  yellow- 
ish-green spotted 
with  brown. 


1.12 


3.53 


2.54 


1.  87         2.  60 


1.55 


71  .99 


15  .  23 


32  .  42 


.18 


29 


Light  green;  lower 
leaves  withered. 

Decided  improve- 
ment over  B2; 
light-green  spot- 
ted with  dark 
green  where  iron 
penetrated. 

Green;  healthy. 

Leaves  rather  light 
green,  showing 
only  few  brown 
spots. 

Few  brown  spots 
on  lower  leaves. 


•About  same  as  C2. 

Much  smaller  than 
Ai;  dark  green; 
roots  formed  fuz- 
zy ball  but  ap- 
parently were 
unable  to  enter 
the  solution. 

Slightly  larger  than 
Di;  dark  green. 


Dark  green. 

Very  stunted; 
leaves  withered; 
only  a  few  strug- 
gling roots  with 
brown  iron  de- 
posit. 

Larger  than  E  j 
with  better  roots. 

About  same  as  Ei. 


20 


BULLETIN   52,    HAWAII   EXPERIMENT   STATION. 


The  results  of  Experiment  IV  are  similar  to  those  of  Experiment 
III.  Manganese  dioxid  with  5,  10,  or  20  milligrams  per  liter  of  iron 
supplied  as  ferric  chlorid  and  18  milligrams  per  liter  of  manganese  as 
manganous  sulphate  (0.005  per  cent  manganous  sulphate)  caused 
chlorosis  and  a  severe  depression  in  growth.  When  the  leaves  were 
dipped  in  iron  solution  the  chlorosis  was  largely  overcome  but  normal 

frowth  was  not  fully  induced.     Very  dark  green  spots  formed  on  the 
ipped  leaves  where  the  iron  penetrated.     The  chlorotic  effects  of 


&  /O      20  40  SO 

M/LUG#tfMf  OF '//eO/V  P£% Z/7Z/P  &//>/*./&?  TO  TH£ 


Fig.  3.— (Results  of  Experiment  V.)     Effect  of  manganous  sulphate  and  maganese  dioxid  on  the  growth 
of  rice  in  nutrient  solutions  supplied  with  various  amounts  of  iron  from  ferric  citrate. 

manganese  were  completely  overcome  when  the  amount  of  iron  in 
the  solution  was  increased  to  40  and  80  milligrams  per  liter,  but  the 
checks  were  injured  by  this  amount  of  iron  from  ferric  chlorid. 
Manganese  dioxid,  by  its  removal  of  some  of  this  excessive  iron,  gave 
slightly  better  results  than  the  check. 

Experiment   V. — This  was  a  repetition  of  Experiment  III.     The 
different  variables  were  the  same  as  in  Experiment  III  except  that 


MANGANESE   CHLOROSIS   OF   PINEAPPLE. 


21 


ferric  citrate  was  substituted  for  ferrous  sulphate  as  the  source  of 
iron  and  the  plants  in  series  A4?  B4,  and  C4  were  dipped  in  a  0.5  per 
cent  solution  of  ferric  citrate  instead  of  ferrous  sulphate. 

The  weights  of  the  plants  on  the  fortieth  day  are  given  in  Table  13 
and  graphically  in  Figure  3. 

Table  13. — Comparative  weights  of  rice  plants  which  were  grown  in  manganous 
sulphate  and  manganese  dioxid  solutions  to  which  were  added  various  amounts 
of  iron  as  ferric  citrate. 


Se- 
ries. 


Culture  solution  with 
amount  of  added  ma- 
terial per  liter. 


Flask 
No. 


Green 
weight 

of 

stalks 

and 

leaves. 


Oven- 
dry 

weight 
of 

stalks 
and 

leaves. 


Oven- 
dry 
weight 

of 
roots. 


Average  oven- 
dry  weight. 


Stalks 

and 
leaves. 


Whole 
plant. 


Condition  of  plants. 


Aj  Sol. +0.005  gm.  Fe  from 
Fej  (CeHsOr)*. 

Aj  Sol. +0.005  gm.  Fe  from 
Fe2(C6HsO7)2+0.4  gm. 
MnOj. 


1-  2 
3-  4 
5-    6 

7-  8 
9-  10 
11-  12 


Aj  i  Sol. +0.005  gm.  Fe  from  1  13-  14 
Fe2(C6H5O:)2+0.018gm.|>  15-  16 
MnfromMnSOi.  |J   17-  18 

A<  Sol. +0.005  gm.  Fe  from 
Fes  (C6H5O-)2+0.4  gm. 
MnOs;  leaves  dipped 
in  a  0.5  per  cent  Fe2 
(C6H50;)2  solution.         jj 

Bi  I  Sol. +0.010  gm.  Fe  from 
Fe2(C6Hs07)2. 

B:     Sol. +0.010  gm.  Fe  from  1 
Fe2(C6H5O:)2+0.4  gm. 
MnOi. 

B3  Sol. +0.010  gm.  Fe  from  I 
Fe2(C6H5O-)2+0.018  |] 
gm.  Mn  from  MnSOi. 

Bi  Sol. +0.010  gm.  Fe  from 
Fe2(C6H5O:)2+0.4  gm. 
MnOif,  leaves  dipped 
in  a  0.5  per  cent  Fe2 
(C6H50r)2  solution. 

Ci  Sol. +0.020  gm.  Fe  from 
Fe2(C6H50:)2. 

C;     Sol. +0.020  gm.  Fe  from 

Fe2(C6H5O:)2+0.4  gm. 

Mn02. 
C3     Sol. +0.020  gm.  Fe  from 

Fei(CeH|07)  2+0.018 

gm.  Mn  from  MnS04. 
C4     Sol. +0.020  gm.  Fe  from 

Fe2(C6H5O7)2+0.4  gm. 

MnO:;    leaves    dipped 

in  a  0.5  per  cent   Fe2 

(C6Hs07)2  solution. 
Di     Sol. +0.040  gm.  Fe  from 

Fe2(CeH507)2. 
D2     Sol. +0.040  gm.  Fe  from 

Fe2(C6H5O7)2+0.4  gm. 

MnOa. 
D3     Sol. +0.040  gm.  Fe  from 

Fe2(C6H507)  2+O.OI8 

gm.  Mn  from  MnS04. 

Ei  Sol. +0.080  gm.  Fe  from 
Fe2(C6H50;)2. 

E2     Sol. +0.080  gm.  Fe  from 

Fe2(C6H5O7)2+0.4  gm. 

MnOj. 
E3  .  Sol. +0.080  gm.  Fe  from 

Fe2(C6H5O:)i  +  0  018 

gm.  Mn  from  MnS04. 


19-  20 
21-  22 
23-  24 

25-  26 
27-  28 
29-  30 
31-  32 
33-  34 
35-  36 
37-  38 
39-  40 
41-  42 

43-  44 
45-  46 
47-  48 

49-  50 
51-  52 
53-  54 
55-  56 
57-  58 
59-  60 
61-  62 
63-  64 
65-  66 


69-  70 
71-  72 

73-  74 

7.5-  76 

77-  7^ 

79-  80 

81-  82 

83-  84 

85-  86 

87-  88 

89-  90 

91-  92 

93-  94 

95-  96 

97-  98 

99-100 

101-102 

103-104 

•105-106 

107-108 


! 

Grams.    Grams. 
15.61         2.41 

14.  16         2.  29 

15.  98         2.  56 


.59 
.85 
.61 

.16 
.15 
.16 

1.60 
1.62 
1.20 

16.85 
17.44 
17.14 
.63 
.53 
.55 
.12 
.13 
.17 

.97 

1.05 

.91 

IS.  33 

18.47 

18.39 

.79 

.95 

1.09 

1.68 

•1.59 

1.44 

3.40 
3.22 
3.88 

17.90 
18.96 
19.40 
5.27 
6.79 
5.67 
9.01 
9.44 
8.78 
15.  27 
16.06 
16.57 
6.47 
6.53 
6.68 
9.84 
9.80 
9.78 


.11 
.18 
.13 

.07 
.07 
.07 

.32 
.25 
.30 

2.99 
3.06 
3.19 
.14 
.13 
.13 
.05 


.23 
.24 
.21 

3.43 
3.34 
3.52 
.20 
.23 
.26 
.42 
.41 
.35 

.73 
.74 

.74 

3.07 
3.40 
3.66 
1.04 
1.25 
1.08 
1.81 
1.95 
1.82 
2.95 
2.86 
3.03 
1.34 
1.36 
1.41 
2.21 
2.08 
2.18 


Grams 
1.00 
.85 
1.06 

.08 
.11 
.07 

.04 
.04 
.04 

.19 
.14 
.17 

1.00 
1.04 
1.10 
.08 
.07 
.07 
.04 
.04 
.05 

.10 
.09 
.13 

1.17 
.95 

1.08 
.11 
.11 
.12 
.18 
.17 
.14 

.37 
.37 

.37 

1.22 

1.31 

1.10 

.56 

.64 

.59 

.59 

.61 

.65 

1.45 

1.53 

1.69 

.65 

.67 

.60 

1.01 

.92 

.98 


Grams. 


Grams. 


2.42 


.14 


.07 


.29 


.23 


3.43 


.23 


.74 


3.38 


1.12 


2.95 


1.37 


2.16 


3.39 


23 


.46 


4.13 


20 


.10 


34 


34 


1.11 


4.59 


1.72 


~2.~48~ 


4.51 
2."6i" 
3.~l3~ 


Fine,  green  plants. 

Very  stunted;  yel- 
lowish-white 
spotted  with 
brown. 

Withered;  brown; 
practically  dead. 

Decided  improve- 
ment over  Aj; 
light  green  spot- 
ted with  dark 
green  where  iron 
penetrated. 

Fine,  dark  green 
plants. 

Same  as  A 2;  leaves 
bleached. 


Same  as  A3. 

Decided  improve- 
ment over  B2; 
light  green  spot- 
ted with  dark 
green  where  iron 
penetrated. 

Fine,  green  plants. 

Yellowish -white; 
stunted;  spotted 
with  brown. 

About  same  as  Cj. 


'Good,  dark  green, 
spotted  with 
very  little 
brown. 

Fine,  green  plants. 

Light  green;  good 
plants  spotted 
with  little  brown 

Same  as  Da. 


Fine,  green  plants. 

Light  green;    very 

few  brown  spots; 

fairly  good  plants. 
Light      green;     no 

brown    spots; 

fairly  good  plants. 


22 


BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 


Manganese  dioxid  with  5,  10,  and  20  milligrams  of  iron  per  liter 
from  ferric  citrate  and  18  milligrams  per  liter  of  manganese  from 
manganous  sulphate  (0.005  per  cent  manganous  sulphate)  caused  a 
strong  chlorosis  and  a  severe  depression  in  growth.  Chlorosis  was 
overcome  and  growth  increased  as  a  result  of  dipping  the  leaves  in 
solutions  of  ferric  citrate.  The  chlorotic  effect  of  manganese  was 
overcome  and  the  weights  approached  those  of  the  checks  when 
the  supply  of  iron  in  the  solution  was  increased  to  40  and  80  milli- 


FlG. 4. 


&  JO       20  40  &O 

(Results  of  Experiment  VI.)    Effect  of  calcium  carbonate  and  manganese  dioxid  on  the  growth  of 
rice  in  nutrient  solutions  supplied  with  various  amounts  of  iron  from  ferrous  sulphate. 


grams.  Here,  where  there  were  no  harmful  effects  due  to  the  pres- 
ence of  excessive  iron  in  the  solutions,  increased  growth  was  not 
made,  because  of  the  presence  of  manganese  dioxid. 

Experiment  VI. — Since  the  action  of  manganese  in  causing  chlo- 
rosis is  similar  to  that  of  calcium  carbonate,  this  experiment  was  made 
to  determine  the  effects  of  the  latter. 

The  weights  of  the  plants  on  the  fortieth  day  are  given  in  Table 
14  and  graphically  in  Figure  4. 


MANGANESE   CHLOROSIS  OF   PINEAPPLE. 


23 


Table  14. — Comparative  weights  of  rice  plants  which  were  grown  in  manganese 
dioxid  and  calcium  carbonate  and  in  calcium  carbonate  solutions  alone,  to  which 
were  added  various  amounts  of  iron  as  ferrous  sulphate. 


Culture  solutions  with 
amount  of  added  mate- 
rial per  liter. 


Flask 
No. 


Green 
weight 

of 

stalks 

and 

leaves. 


Oven- 
dry 

weight 
of 

stalks 
and 

leaves. 


Oven- 
dry 
weight 

of 
roots. 


Average  oven- 
dry  weight. 


Stalks 


Whole 


kavt.le'-t- 


Condition  of  plants. 


Ai 

*      M 


A3 


Aj 


C2 

C3 
Ct 

T>i 
D2 

Dj 

Ei 
E2 


Sol. +0.005  gm.  Fe  from 
FeSO*. 

Sol.+0.005  gm.  Fe  from 
FeSO4+0.4  gm.  Mn02+ 
0.4  gm.  CaC03. 

Sol.+0.005  gm.  Fe  from 
FeSO4+0.4gm.  CaCOs, 

Sol.+0.005  gm.  Fe  from 
FeSO4+0.4gm.  Mn02+ 
0.4  gm.  CaCOs;  leaves 
dipped  in  0.5  per  cent 
FeS04  solution. 

Sol. +0.010  gm.  Fe  from 

FeS04. 
Sol.+O.OlO  gm.  Fe  from 

FeSO4+0.4gm.MnO2-f 

0.4  gm.  CaC03. 

Sol.+O.OlO  gm.  Fe  from 
FeSO4+0.4gm.  CaC03. 

Sol.+O.OlO  gm.  Fe  from 
FeSO4+0.4  gm.  Mn02+ 
0.4  gm.  CaCOs;  leaves 
dipped  in  0.5  per  cent 
FeS04  solution. 

Sol. +0.020  gm.  Fe  from 
FeS04. 

Sol.+0.020  gm.  Fe  from 
FeSO4+0.4gm.MnO2+ 
0.4  gm.  CaC03. 

Sol. +0.020  gm.  Fe  from 
FeSO4+0.4gm.CaCO3. 

Sol. +0.020  gm.  Fe  from 
FeSO4+0.4gin.MnO2+ 
0.4  gm.  CaC03;  leaves 
dipped  in  0.5  per  cent 
FeS04  solution. 

Sol. +0.040  gm.  Fe  from 
FeS04. 

Sol. +0.040  gm.  Fe  from 
FeSO4+0.4  gm.  Mn02+ 
0.4  gm.  CaC03. 

Sol. +0.040  gm.  Fe  from 
FeSO4+0.4gm.  CaC03. 

S0I.+O.O8O  gm.  Fe  from 
FeSO«. 

Sol. +0.080  gm.  Fe  from 
FeSO4+0.4  gm.Mn02+ 
0.4  CaC03. 

Sol. +0.080  gm.  Fe  from 
FeSO4+0.4  gm.  CaC03. 


1-  2 

3-  4 
5-  6 
7-  8 
9-10 
11-12 

13-14 
15-16 
17-18 


19-20 
21-22 
23-24 

25-26 
27-28 
29-30 
31-32 
33-34 
35-36 
37-38 
39-40 
41-42 

43-44 
45-46 

47-48 

49-50 
51-52 
53-54 
55-56 
57-58 
59-60 
61-62 
63-64 
65-66 

67-68 
69-70 
71-72 

73-74 
75-76 
77-78 
79-80 
81-82 
83-84 
85-86 
87-88 


Grams. 

13.07 

13.48 

12.98 

.27 

.26 

.28 

.85 
.82 
.74 


91-92 

93-94 

95-96 

97-98 

99-100 

[101-102 

103-104 

105-106 

107-108 


Grams. 

2.  73 

2.66 

.10 

.10 

.10 

.21 
.20 

.17 


4.29 
4.30 
4.43 

12.38 
14.86 
12.97 
.22 
.18 
.23 
.62 
.81 
.83 

3.14 
3.66 
3.51 

14.11 

13.37 

15.15 

.20 

.21 

.24 

5.00 

4.58 

5.  It) 

1.22 
1.47 
1.24 

11.82 

12.17 

12.74 

.47 

.52 

.64 

10.68 

11.55 

11.59 

5.97 

7.24 

5.78 

5.13 

4.50 

5.32 

11.61 

12.58 

11.25 


2.62 
2.76 
2.75 
.08 
.06 
.09 
.16 
.20 
.21 


.71 
.71 

2.71 

2.64 

2.73 

.07 

.07 


.97 
.97 

.27 
.34 
.30 

2.60 
2.97 
2.74 
.15 
.15 
.19 
2.14 
2.31 
2.29 
1.52 
1.64 
1.45 
1.05 
1.12 
1.22 
2.20 
2.52 
2.31 


Grams. 
0.75 
.77 
.77 
.07 
.07 
.07 

.11 


.82 
.88 
.05 
.05 
.06 
.36 
.34 
.35 

.13 
.13 

.16 

.87 
1.02 


.11 
.12 
.67 
.67 
.79 
.51 
.56 
.50 
.35 
.34 
.42 
.73 
.72 
.72 


Grams. 


2.69 


2.71 


Grams. 


1.01 


.30 


2.77 


2.25 


1.54 


1.13 
"2.~34 


3.45 


.30 


1.20 


3.55 


Fine,green,healthy . 

1  Bleached  white; 
spotted  with 
brown;  stunted. 
Yellowish-w  h  i  t  e; 
faint,  green, 
brown  spots;  lit- 
tle better  than 
A2. 

Green  and  healthy; 
dark  green  spots 
where  iron  pene- 
trated. 

Green;  healthy. 


.28 


1.00 


3.55 


.13 
"l."36 


.44 


with- 


2.96 


2.06 
T50" 
"3.~06" 


Same  as  A2; 
ered. 

Same  as  A3. 


Same  as  A4. 


•Green;  healthy. 


•Same  as  Bi. 

Light  yellowish- 
green;  somewhat 
stunted. 


•Same  as  A4. 


Green;  healthy. 

Yellowish  -green 
spotted  with 
brown;  stunted. 

Somewhat  light  in 
color. 

Green;  healthy; 
roots  injured  by 
excessive  iron. 

Light  green;  rather 
stunted. 

Fine,  dark-green 
plants. 


Calcium  carbonate  with  5  and  10  milligrams  per  liter  of  iron 
supplied  from  ferrous  sulphate  caused  a  strongly  chlorotic  condition 
and  severe  depression  in  growth.  Chlorosis  almost  disappeared  with 
20  milligrams  and  did  not  occur  at  all  with  40  and  80  milligrams. 
In  fact,   with  80  milligrams  calcium  carbonate  caused  a  decided 


24  BULLETIN   52,    HAWAII   EXPERIMENT   STATION. 

increase  in  growth  due  to  its  removal  of  some  of  the  excessive  iron 
present. 

Manganese  dioxid  and  calcium  carbonate  combined  with  5,  10, 
20,  and  40  milligrams  per  liter  of  iron  caused  a  strong  chlorosis  and 
a  severe  depression  in  growth.  The  chlorosis  was  overcome  when  the 
leaves  were  dipped  in  iron  or  when  the  iron  supply  was  increased  to 
80  milligrams. 

Experiments  III  and  VI  may  be  considered  together  since  the 
plants  were  grown  in  each  for  the  same  length  of  time  with  the  same 
solutions  and  each  had  approximately  the  same  check.  This  has 
been  done  in  Figure  4.  A  study  of  Tables  3  and  6  and  Figure  4 
indicates  that  calcium  carbonate  and  manganese  dioxid  have  the 
same  effects.  Although  the  above-mentioned  results  were  obtained 
when  calcium  carbonate  and  manganese  dioxid  were  used  singly  in 
excessive  amounts,  the  chlorosis  was  very  greatly  increased  when 
the  two  were  used  in  combination.  Manganese  dioxid  and  calcium 
carbonate  each  appears  to  possess  its  own  peculiar  chlorotic  effect 
and  to  exert  an  additive  chlorotic  effect  in  the  presence  of  the  other. 

Discussion  of  Results. 

The  results  obtained  show  that  manganous  sulphate  and  manga- 
nese dioxid  cause  a  strong  chlorosis  and  a  severe  depression  in  the 
growth  of  the  plant.  This  chlorosis  is  overcome  when  the  leaves  are 
dipped  in  iron  solutions  or  when  the  amount  of  iron  in  the  nutrient 
solution  is  excessively  increased.  Manganese  thus  apparently 
causes  a  depression  in  the  assimilation  of  iron  by  the  plant  or  a 
deficiency  of  iron  in  the  plant.  This  confirms  the  results  with  pine- 
apples previously  obtained  by  the  writer.  Many  investigators  have 
found  that  manganese,  especially  in  large  amounts,  causes  chlorosis, 
but  none  has  offered  proof  to  show  that  manganese-induced  chlorosis 
is  due  to  a  depression  in  the  assimilation  of  iron  or  to  a  deficiency  of 
iron  in  the  plant. 

Manganese-induced  chlorosis  occurs  in  acid  solution  and  is  alto- 
gether distinct  from  lime-induced  chlorosis  which  is  caused  by 
calcium  carbonate.  In  the  latter  instance  the  availability  of  the  iron 
is  reduced  by  the  alkalinity  of  the  solution.  Manganese  and  calcium 
carbonate  can  each  exert  an  additive  chlorotic  effect  in  the  presence 
of  the  other. 

Since  chlorosis  is  produced  by  manganese  in  acid  solutions  with  no 
excess  of  lime,  it  is  proved  conclusively  that  chlorosis  in  general  is 
not  due  to  the  alkalinity  of  the  solutions  or  to  excess  of  lime,  but 
simply  to  deficiency  in  iron. 

Manganese  is  commonly  referred  to  as  a  plant  stimulant.  In 
these  experiments  manganese  has  been  found  to  cause  increased 
growth  only  when  the  solution  contained  a  large  excess  of  iron,  some 
of  which  the  manganese  dioxid  removed. 

AN  EXPLANATION  OF  THE  PHYSIOLOGICAL  EFFECTS  OF  MANGANESE 

ON  PLANTS. 

Pugliese  (37)  and  Tottingham  and  Beck  (44)  have  suspected  an 
antagonism  between  manganese  and  iron.  In  the  writer's  opinion, 
however,  the  physiological  effect  of  manganese,  at  least  the  effect  of 
the  manganiferous  soils,  can  be  explained  on  purety  chemical  grounds. 
Hildebrand  (22)  gives  a  titration  curve  for  ferrous  sulphate  in  which 


.MANGANESE    CHLOEOSIS    OF    PINEAPPLE. 


25 


the  hydrogen-ion  concentration  of  the  solution  is  determined  at 
various  stages  of  titration  with  sodium  hydroxid.  Ferrous  hydroxid 
was  not  precipitated  until  the  solution  was  made  quite  alkaline. 
Ferric  salts  could  not  be  investigated  with  the  hydrogen  electrode,  but 
Hildebrand  predicts  "that  they  would  behave  very  much  like 
aluminum  salts/'  which  are  precipitated  while  the  solution  is  still 


/.O 


2.0 


&o 


4.0 


^  7.0 


8.0 
9.0 

/ao 

MO 


TO /=>£J?NT<S. 


F£T*/?06& //?M  JV/9S  0£- 


il 


X 

rt/GHL  Y  C/JLCfffi£- 
OC/S  SO/LS. 


/O 


ao  <3o  *o 


KfO 


eo 


Fig.  5.— Titration  curves  of  ferric  and  ferrous  salts  with  alkali. 


strongly  acid.     This  work  of  Hildebrand  seems  to  furnish  a  clue  to 
the  manner  in  which  chlorosis  is  induced. 

In  order  to  investigate  this  more  fully  the  titration  curve  of  ferric 
chlorid  was  determined.  Various  amounts  of  0.2N  sodium  hydroxid 
were  added  to  50  cubic  centimeter  portions  of  a  roughly  0.2 X  solu- 
tion of  ferric  chlorid.  The  solutions  were  filtered  and  the  hydrogen- 
ion  concentration  of  the  filtrate  was  determined  by  the  colorimetric 
method  of  Clark  and  Lubs  (11).  This  titration  curve  for  ferric 
chlorid  is  given  in  Figure  5.     By  careful  titration,  it  was  easy  to 


26  BULLETIN    52,    HAWAII   EXPERIMENT   STATION. 

show  that  ferric  iron  was  completely  precipitated  while  the  solution 
was  still  strongly  acid  because  a  colorless  filtrate  could  be  obtained 
showing  a  pH  value  of  about  4.4.  No  trace  of  iron  could  be  detected 
by  the  sulphocyanate  method  in   this  colorless  acid  filtrate. 

Apparently  ferric  iron  is  unavailable  to  many  plants  on  most  soils 
since  it  is  completely  precipitated  while  the  solution  is  still  strongly 
acid  and  becomes  available  only  when  it  is*  reduced  to  the  ferrous 
form.  This  would  emphasize  a  hitherto  neglected  function  of  humus 
and  organic  matter  in  the  soil.  In  Figure  5  is  also  given  the  titration 
curve  for  ferrous  sulphate.  This  is  not  very  accurate  because  oxida- 
tion took  place  during  titration,  but  is  chiefly  of  interest  in  showing 
that  a  strong  test  for  soluble  ferrous  iron  could  be  obtained  when  the. 
solution  was  decidedly  alkaline.  Although  possibly  modified  by  the 
presence  of  other  ions,  this  fundamental  difference  between  the 
solubilities  of  ferric  and  ferrous  iron  throws  much  light  on  the  manner 
in  which  chlorosis  is  induced. 

Figure  5  explains  very  clearly  why  chlorosis  is  induced  on  the 
manganiferous  Hawaiian  soils.  In  soils  containing  an  excess  of 
manganese  dioxid  the  iron  is  kept  oxidized  to  the  ferric  form  and, 
consequently,  is  not  sufficiently  available  to  the  plants,  at  least  to 
those  susceptible  to  chlorosis.  Any  iron  which  is  added  to  the  soil 
is  immediately  rendered  unavailable  and  the  effect  of  such  soil  then  is 
depression  in  the  assimilation  of  iron  by  plants  growing  on  them. 

This  explanation  also  applies  to  the  effect  of  manganese  dioxid  in 
nutrient  solution.  The  explanation  is  not  so  simple  in  case  of  man- 
ganous  sulphate.  Deatrick  (12)  has  shown  that  the  brownish-black 
deposit  which  forms  on  the  roots  of  plants  that  are  growing  in  solu- 
tions containing  manganous  salts  is  a  deposit  of  manganese  dioxid. 
A  like  deposit  very  probably  occurs  also  in  the  tissues  of  the  plant, 
and,  if  so,  naturally  hinders  the  assimilation  of  iron,  as  previously 
described. 

In  addition  to  explaining  the  manner  in  which  chlorosis  is  induced 
on  manganese  soils,  Figure  5  throws  much  light  on  Gile's  work  on 
lime-induced  chlorosis.  Chlorosis  will  not  occur  on  calcareous  soils 
in  the  presence  of  plenty  of  organic  matter  or  of  other  material 
which  is  capable  of  furnishing  a  supply  of  ferrous  iron  notwithstand- 
ing the  fact  that  oxidation  of  ferrous  iron  occurs  readily  and  reduction 
of  the  ferric  iron  to  the  available  ferrous  form  is  difficult  in  strongly 
alkaline  solutions.  This  explains  why  Gile  (15)  did  not  find  chlorosis 
in  pineapples  when  large  amounts  of  calcium  carbonate  were  added 
to  a  soil  which  was  very  rich  in  humus.  Moreover,  it  explains  why 
Gile  and  Carrero  (20)  found  that  rice  becomes  chlorotic  in  calcareous 
soils  with  ordinary  percentages  of  water,  but  grows  normally  when 
the  soil  is  submerged.  Reducing  conditions  of  course  prevail  in  sub- 
merged soil  and  ferrous  iron  is  then  available  to  the  plant. 

The  chief  problem  remaining  unsolved  in  connection  with  chlorosis 
is  why  on  the  same  soil,  either  manganiferous  or  calcareous,  some 
plants  become  chlorotic  while  others  do  not.  The  manner  in  which 
susceptible  plants  become  chlorotic  has  been  explained.  Plants  that 
are  immune  apparently  obtain  sufficient  iron  for  their  requirements, 
either  because  such  requirements  are  very  small  or  through  some 
special  relation  of  their  roots  to  the  soil.  It  is  suggested  that  those 
who  are  interested  in  this  problem  grow  both  susceptible  and  immune 


MANGANESE    CHLOROSIS   OF    PINEAPPLE.  27 

plants  under  comparative  conditions  and  in  nutrient  solutions  con- 
taining varying  amounts  of  iron  and  having  the  availability  of  the 
iron  diminished  by  the  addition  of  manganese  dioxid  or  calcium  carbon- 
ate. The  results  of  such  tests  should  indicate  whether  plants  differ 
greatly  in  their  iron  requirements  or  whether  the  resistance  to  chlorosis 
is  due^  to  some  special  relation  of  the  plants'  roots  to  the  soil. 

A  SUCCESSFUL  TREATMENT  FOR  THE  YELLOWING  OF  PINEAPPLES 
ON  MANGANIFEROUS  SOILS. 

i 

RESULTS  OF  SUPPLYING  IRON  TO  THE  PLANTS. 

Since  the  injurious  effects  of  manganese  seem  to  be  due  simply  to  a 
deficiency  of  iron  in  the  plant,  attempts  were  made  to  overcome 
" manganese  poisoning"  occurring  on  manganiferous  Hawaiian  soils 
by  supplying  the  plants  with  iron.  Experiments  were  made  with  the 
pineapple  crop  because  of  its  susceptibility  to  injury  and  the  fact 
that  it  is  the  principal  crop  of  economic  importance  in  the  region 
where  the  manganese  soils  occur. 

Experiment  I. — An  effort  was  made  to  overcome  the  toxic  effects 
of  the  manganese  by  supplying  sulphate  of  iron  and  sulphuric  acid 
to  the  soil  in  pot  experiments.  Young  pineapple  plants  which  were 
transferred  from  a  normal  soil  to  a  manganese  soil  to  which  iron 
sulphate  had  been  applied  gave  better  results  than  did  plants  which 
were  transferred  to  manganese  soil  alone. 

In  a  series  of  pot  experiments  25  pounds  of  manganese  soil  was 
used  for  each  pot  in  which  a  pineapple  plant  was  grown.  Six  pots 
were  used  as  checks.  Ferrous  sulphate  (copperas)  was  applied  to 
4  pots  at  the  rate  of  500  pounds  per  acre  and  to  4  others  at  the  rate 
of  1,000  pounds  per  acre.  Stable  manure  at  the  rate  of  12  tons  per 
acre  was  applied  to  4  pots  and  sulphuric  acid  (strength  66°)  was 
added  at  the  rate  of  1.000  pounds  per  acre  to  2  other  pots.  Twenty 
pineapple  plants  of  equal  size  and  appearance  were  selected  from  a 
large  number  of  plants  and  set  in  these  pots  for  observation. 

The  plants  in  pots  to  which  ferrous  sulphate  had  been  added  made 
a  slightly  better  growth  at  first  than  did  the  others.  With  sulphuric 
acid  a  slight  stunting  was  evident  in  the  earlier  stages,  but  in  a  short 
time  no  difference  was  observed  between  these  and  the  check  plants. 
Plants  in  pots  to  which  stable  manure  was  applied  were  apparently 
the  same  as  the  checks. 

At  the  expiration  of  five  months  all  of  the  pineapple  plants  were 
fairly  uniformly  yellow  and  none  of  the  treatments  applied  to  the 
soil  had  any  beneficial  effect.  A  solution  of  iron  sulphate  was  then 
applied  to  the  leaves  of  these  yellow  plants  with  the  result  that  the 
normal  careen  color  and  healthy  appearance  was  restored. 

Experiment  II. — Experiments  on  plants  in  the  field  were  under- 
taken in  cooperation  with  the  Hawaiian  Pineapple  Co.  The  leaves 
of  yellow  pineapple  plants  in  a  field  suffering  from  a  severe  case  of 
"manganese  yellows "  were  brushed  four  times  at  intervals  of  a  week 
with  a  2  per  cent  solution  of  iron  sulphate.  Two  weeks  after  the 
brushings  were  completed  a  striking  change  was  noticeable,  and  in  a 
month's  time  the  plants  had  resumed  their  green  color  and  were 
making  vigorous  growth.  The  condition  of  the  untreated  plants 
adjoining  was  unchanged.     Since  then  this  field  has  been  sprayed 


28  BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 

with  iron  sulphate  solution,  and  all  of  the  plants  have  made  normal 
growth. 

Experiment  III. — To  show  that  it  is  the  iron  that  is  effective  in 
restoring  the  normal  green 'color  and  health  to  the  plant,  and  to 
ascertain  the  effects  of  some  fertilizing  elements  in  combination  with 
iron,  the  leaves  of  very  yellow  plants  were  brushed  four  times  at 
intervals  of  a  week  each  with  various  solutions  and  the  condition  of 
the  plants  was  observed  one,  two,  and  three  months  later. 

It  was  observed  that  the  plants  which  were  brushed  with  a  2  per 
cent  solution  of  iron  sulphate  gave  results  similar  to  those  obtained 
in  Experiment  II,  and  that  other  plants  were  not  benefited  by  the 
application  of  a  pint  of  the  solution  to  the  soil  near  the  roots.  "  The 
application  to  the  roots  of  several  ounces  of  iron  sulphate  crystals 
was  of  some  benefit,  but  not  nearly  so  much  so  as  was  the  applica- 
tion to  the  leaves  of  the  solution  containing  a  small  amount  of  iron 
sulphate.  No  change  was  noted  in  plants  which  were  brushed  with 
a  4  per  cent  solution  of  sulphuric  acid,  and  very  slight  change  oc- 
curred when  dilute  acid  was  applied  to  the  soil  in  quantities  of  one- 
half  pint  and  1  pint  per  plant.  Plants  which  were  brushed  with  a 
2  per  cent  solution  of  ferric  chlorid  (iron  chlorid)  appeared  better 
than  did  those  which  were  brushed  with  iron  sulphate,  having  a 
fine,  -dark  green  color.  The  chlorid,  however,  has  a  tendency  to 
burn  the  plants.  The  application  of  ferric  chlorid  to  the  soil  was  of 
very  little  benefit  to  the  plants.  The  application  of  a  solution  of 
soluble  ferric  phosphate  to  the  leaves  of  the  pineapple  plant  was  of 
some  benefit,  but  the  application  of  solutions  and  crystals  to  the 
soil  near  the  roots  was  of  little  value.  Ferric  ammonium  sulphate 
when  applied  to  the  leaves  in  solution  and  as  crystals  to  the  roots 
was  beneficial,  but  solutions  applied  to  the  roots  had  no  effect. 

In  order  to  secure,  if  possible,  beneficial  action  similar  to  that  se- 
cured from  the  use  of  stable  manure,  due  to  solvent  action  of  organic 
acids,  2  per  cent  solutions  of  citric,  oxalic,  and  acetic  acids  were  ap- 
plied to  the  soil  near  the  roots  of  the  plants  but  without  noticeable 
results.  It  would  seem  that  the  temporary  beneficial  action  of  the 
manure  is  to  be  ascribed  to  the  growing  of  the  plant  in  the  manure 
rather  than  in  the  manganese  soil,  as  it  was  necessary  to  apply  large 
amounts  of  the  manure  to  the  rows.  An*  injection  of  iron  sulphate 
near  the  base  of  yellow  plants  was  of  little  value. 

Sulphuric  acid  added  in  quantities  of  1  per  cent  to  the  iron  sul- 
phate solution  gave  results  slightly  more  beneficial  than  when  iron 
sulphate  alone  was  used  but  showed  an  increased  tendency  toward 
burning.  A  solution  containing  4  per  cent  of  ammonium  sulphate 
in  addition  to  the  iron  sulphate  gave  beneficial  results.  Spraying 
with  solutions  containing  ammonium  sulphate  in  addition  to  the  iron 
sulphate  seems  to  be  of  value  in  that  it  supplies  ammonium  salts 
which  are  known  to  be  of  benefit  to  pineapples. 

From  these  trials  it  is  evident  that  the  restoration  of  the  normal 
green  color  and  healthy  appearance  of  the  plants  is  due  to  the  iron 
which  is  contained  in  the  iron  sulphate  solution  applied  to  the  leaves. 
That  it  is  not  due  to  acidity  of  the  salts  or  the  sulphate  radical  is 
shown  by  the  unsuccessful  results  when  solutions  of  sulphuric  acid 
were  applied  to  the  leaves. 

Experiment  IV. — Previous  experiments  having  indicated  that  the 
application  to  the  leaves  of  solutions  of  iron  sulphate  alone,  of  iron 


MANGANESE    CHLOROSIS    OF    PINEAPPLE. 


29 


sulphate  with  acids,  and  of  ferric  chlorid  (chlorid  of  iron)  is  the 
most  practical  field  treatment  for  pineapple  plants  growing  on 
manganese  soils,  these  treatments  were  compared  in  a  more  extensive 
investigation  and  the  effects  of  1,  2,  3,  and  4  applications,  and  of  5 
different  strengths  of  the  three  solutions  were  observed. 

A  search  in  1918  by  C.  W.  Carpenter  (10),  then  station  pathologist, 
having  shown  the  presence  of  stomata  on  the  underside  of  the  pine- 
apple leaves  at  the  bottom  of  the  grooves  of  the  slightly  ridged  sur- 
face, it  was  thought  that  spraying  the  under  surface  of  the  leaves 
with  iron  solutions  might  be  more  effective  than  spraying  the  upper 
surface  of  the  leaves.  Accordingly,  an  experiment  was  made  in  a 
large  field  of  uniformly  yellow  plants  which  were  sprayed  once  a 
week  with  iron  solutions.  The  general  results  of  this  experiment 
were  judged  two  months  after  the  first  application  had  been  made 
and  were  confirmed  by  observations  at  other  times. 

Table  15. — Results  of  various  sprayings  of  pineapple  plants  on  highly  manganifer- 
ous  soils  with  solutions  of  various  strengths  of  iron  sulphate,  iron  sulphate  with 
acids,  and  ferric  chlorid. 


Strength 

of 
solution. 

Method  of  appli- 
tion. 

Number 
of  appli- 
cations. 

Improvement  made  by  plants  treated  with— 

Ferric  chlorid. 

Iron  sulphate. 

Iron  sulphate   +    1 
per   cent  sulphu- 
ric acid. 

Per  cent. 
0.5 

Upper 

1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 

Slight  . 

Slight..- 

do 

do 

Slight. 

.5 

.5 

do 

do 

do 

Under 

do 

..  do.. 

Do. 
Do. 

.5 

do 

do 

do 

do 

Do. 
Do. 

.5 

do 

do 

do 

Upper 

do 

do 

Do. 

.5 
.5 
1.0 

do 

Fair 

Slight 

do 

do 

...do.. 

Do. 
Do. 

Do. 

1.0 
1.0 
1.0 

do 

do 

do 

Under ... 

do 

do 

Fair.  .... 

do 

do 

Fair    . 

Do. 
Do. 
Fair. 

1.0 

Slight  . 

Slight 

Slight. 

1.0 

do 

do 

do 

Upper..        

do... 

do 

Do. 

1.0 
1.0 

Fair 

do 

Slight 

Fair 

do 

Fair 

Do. 

Fair. 

2.0 

Slight 

do . 

Slight. 

2.0 

do 

Do. 

2.0 
2.0 

do 

do 

Under.  

do 

Green. ..  .        ... 

do 

Fair 

Fair. 
Green. 

2.0 

1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 
1 

: 

4 

I 

Slight 

Slight     - 

Slight. 

2.0 

do 

do 

Fair 

Fair.-. 

Do. 

2.0 

do 

do 

Fair. 

2.0 
4.0 

do. 

Upper. 

do 

Slight 

do 

Slight 

Green. 
Fair. 

4.0 

do 

do 

do 

Under ... 

Fair 

Fair 

Do. 

4.0 

do 

do 

Green. 

4.0 

do 

Green 

Do. 

4.0 

Slight 

Fair 

Fair. 

4.0 

do 

do 

......do 

Fair 

.do. 

Green. 

4.0 
4.0 

do 

do 

Do. 
Do. 

8.0 

Upper 

Slight     . 

Fair 

Fair. 

8.0 

do 

do 

do 

Under. . 

Faii- 

.--.do.-- -. 

Green. 

8.0 
8.0 

Green 

do 

Dark  green. 
Do. 

8.0 

Slight 

Fair  .. 

Fair. 

8.0 

do.... 

Green. 

8.0 

do 

do 

do 

do 

Dark  green. 

8.0 

16.0 

4  j  Dark  green 

1             do 

do .-. 

Fair 

Do. 
Fair. 

16.0 

do 

do.... 

do.... 

Under 

2 

3 
4 

1 
L2 
3 
4 

do... 

do 

do 

do... 

...do 

16.0 
16.0 
16.0 

do 

do 

Fair 

Dark  green. 

Do. 
Fair. 

16.0 

do. 

16.0 

do... 

do 

do 

16.0 

do 

...  .do.. 

Do. 

30  BULLETIN    52,    HAWAII   EXPEEIMENT    STATTOX. 

The  value  of  each  of  these  numerous  treatments  was  judged  by 
the  average  restoration  of  the  green  color  and  the  general  health  and 
vigor  of  the  plants  treated  in  comparison  with  the  plants  in  the  check 
rows  and  with  those  receiving  different  treatments.  Table  15  gives 
the  results  of  these  treatments. 

Table  15  shows  that  ferric  chlorid  is  not  to  be  recommended  for 
field  use.  In  most  cases  it  was  only  slightly  more  effective  than  iron 
sulphate,  but  even  a  4  per  cent  solution  burned  the  plants  somewhat. 
The  high  cost  of  ferric  chlorid  is  also  a  drawback  to  its  use. 

The  application  of  iron  solutions  to  the  under  surface  of  the  leaves 
gave  slightly  better  results  in  most  instances  than  did  spraying  the 
upper  surface,  but  there  was  a  greater  tendency  toward  burning. 
The  results  obtained  were  not  such  as  would  justify,  for  present  large- 
scale  practice,  the  spraying  of  plants  from  below.  The  addition  of 
acids  slightly  increased  the  effectiveness  of  the  iron  sulphate  but  did 
not  prevent  burning  in  some  cases. 

The  most  practical,  convenient,  and  economical  treatment  ap- 
peared to  be  the  application  to  the  plants  of  three  or  four  sprayings 
of  an  8  per  cent  solution  of  iron  sulphate.  A  16  per  cent  solution 
was  more  effective  than  the  latter  but  burned  the  plants  considerably. 

RESULTS  OF  SOIL  TREATMENT. 

An  experiment  was  made  in  cooperation  with  F.  K.  Benedict,  of 
Libby,  McNeill  &  Libby,  Honolulu,  in  which  flowers  of  sulphur  was 
applied  to  a  manganese  soil  in  field  plats  at  the  rate  of  500  to  3,000 
pounds  per  acre.  Additions  of  a  red,  very  acid,  upland  soil  con- 
taining apparently  considerable  quantities  of  available  iron  were  also 
made  to  the  manganese  soil  at  the  rates  of  1  to  6  tons  per  acre.  A 
third  treatment  tried  was  the  application  to  the  soil  of  bagasse  soaked 
in  very  strong  solutions  of  iron  sulphate.  None  of  the  treatments 
was  effective,  the  treated  plats  yellowing  as  did  the  check  plats. 
Even  when  the  solution  carried  by  the  bagasse  contained  3,000 
pounds  per  acre  of  iron  sulphate  no  effect  was  apparent.  The  yellow 
plants  in  this  experiment  oecame  green  rapidly  and  made  vigorous 
growth  when  they  were  sprayed  with  only  a  few  pounds  per  acre  of 
iron  sulphate  in  solution.  The  plants  on  the  sulphur  plat  showed 
some  stimulation  caused  by  the  sulphur. 

PRACTICAL  TESTS  OF  THE  METHOD  OF  SPRAYING. 

THE  SPRAYER  USED. 

The  benefits  resulting  from  spraying  yellow  pineapple  plants  on 
manganese  soils  with  iron  solutions  were  so  evident  that  the  cooper- 
ating plantation  applied  this  treatment  as  soon  as  possible  to  all  of  its 
fields  where  " manganese  yellows"  appeared.  Check  rows  only  were 
left  unsprayed.  As  a  spraying  machine  could  not  easily  be  secured, 
a  hand  sprinkler  was  used  at  first  with  fairly  good  results.  An 
ingenious  modification  of  the  old  carbon  dioxicl  orchard  spray  was 
devised  for  the  first  large-scale  treatments  of  extensive  areas.  This 
sprayer  was  designed  by  S.  T.  Hoyt,  of  the  Hawaiian  Pineapple  Co., 
and  was  built  at  a  low  cost  by  the  plantation  blacksmith.  The 
sprayer  is  mounted  on  a  single  iron  wagon  wheel,  so  that  turning  is 
easy  at  the  end  of  the  rows.  It  holds  30  gallons  of  iron  sulphate  solu- 
tion.    An  ordinary  carbonic-acid  tank  in  the  rear  furnishes  pressure 


MANGANESE   CHLOROSIS   OF   PINEAPPLE.  31 

sufficient  for  spraying.  Pipes  lead  from  the  rear  to  the  front  tank 
and  from  the  front  tank  to  the  spray  nozzles,  which  are  placed  on  the 
long  arm  extending  crosswise  from  the  sprayer.  A  gauge  on  the  front 
tank  sh  ws  the  pressure,  which  is  kept  at  about  30  to  40  pounds  when 
spraying.  (PI.  II,  figs.  1  and  2.)  As  the  machine  moves  forward  it 
sprays  lour  rows  at  a  time.  Many  complicated  sprayers  have  been 
tried  by  the  various  plantation  managers,  but  the  single-wheel  type 
of  sprayer,  similar  to  that  described  above,  is  satisfactorily  used  by 
most  of  them.  The  principal  modification  has  been  in  the  use  of  an 
air  compressor  which  is  driven  from  the  large  supporting  wheel  to 
furnish  the  pressure  and  to  take  the  place  of  the  more  expensive 
carbon-dioxid  tank,  or  the  use  of  a  pump  similarly  driven  which 
delivers  the  solution  from  the  tanks  to  the  spraying  nozzles  under 
pressure. 

SPRAYING  COSTS. 

The  cost  of  spraying  is  considered  negligible  in  comparison  with  the 
expenditures  necessary  in  the  raising  of  pineapples.  With  the 
experimental  sprayer  described  above  the  cost  amounted  to  approxi- 
mately 60  cents  per  acre  for  each  spraying.  The  yearly  cost  per  acre 
for  spraying  is  not  large,  since  the  fields  are  sprayed  on  the  average 
only  about  once  a  month. 

SMALL  FIELD  TESTS. 

All  of  the  fields  of  the  cooperating  plantation  where  u  manganese 
yellow"  was  evident  were  sprayed  with  excellent  results.  The  man- 
ganiferous  soil  had  been  particularly  injurious  in  one  large  field  of 
young  plants.  A  sample  of  the  soil  from  this  field,  given  in  Table 
2  as  No.  636,  showed  4.8  per  cent  of  manganese  as  Mn304.  The 
plants  throughout  the  field  were  very  yellow  and  showed  no  trace  of 
green,  while  many  of  the  plants  which  were  about  six  months  old  had 
turned  brown  from  the  tips  of  the  leaves .  and  were  dying.  The 
spra}'ing  treatment  was  applied  with  immediate  benefit,  and  in  six 
months'  time  the  whole  field  presented  a  very  vigorous  green  and 
healthy  appearance. 

A  130-acre  field  was  given  three  sprayings  about  the  time  of 
flowering  or  later  in  May  and  June.  This  field  was  not  wholly 
uniform,  the  plants  in  some  sections  appearing  slightly  affected  and 
in  others  showing  very  decided  effects  from  the  manganiferous  soils. 
Immediate  results  were  evident  when  the  spraying  treatment  was 
applied  to  the  whole  field,  the  plants  becoming  green  and  vigorous 
and  the  stunted  fruit  rapidly  developing  green  color  and  making 
vigorous  growth.  The  results  of  analysis  of  a  sample  of  this  soil, 
taken  under  the  green  sprayed  plants,  show  5.58  per  cent  of  man- 
ganese present  as  Mn304.  (See  Table  2,  No.  640.)  An  adjoining 
unsprayed  check  row  was  very  yellow  and  bore  small  red  fruit.  The 
plantation  records  of  this  field  show  an  average  yield  of  about  13  tons 
of  fruit  per  acre. 

MAIN  FIELD  TEST. 

The  field  in  which  this  test  was  made  lies  in  the  Halemanu  district 
of  Oahu,  where  the  most  highly  manganiferous  soils  occur.     The 

Elantings  were  made  on  virgin  soil  to  which  commercial  fertilizer  had 
een  applied  at  the  rate  of  600  pounds  per  acre.     As  the  formula  for 
this  fertilizer  is  the  property  of  the  cooperating  plantation,  it  can  not 


32  BULLETIN    52,    HAWAII   EXPERIMENT   STATION. 

be  given  here,  but  the  condition  of  the  plants  in  the  check  rows 
showed  that  '  'manganese  yellows"  can  not  be  overcome  by  use  of  the 
ordinary  fertilizers. 

This  field  was  given  three  sprayings  with  the  experimental  sprayer 
previously  described.  Some  parts  of  this  field  were  not  sprayed 
until  June.  So  severe  were  the  effects  of  the  manganese  that  a  great 
number  of  plants  appeared  to  be  destroyed,  but  a  vigorous  growth 
of  green  suckers  as  a  result  of  the  spraying  produced  a  good  ratoon 
crop. 

Fart  of  the  field  on  which  this  experiment  was  made  was  sprayed 
three  times  in  April.  Previous  to  this  the  plants  had  been  gone  over 
four  times  with  a  hand  sprinkler  containing  a  solution  of  iron  sul- 
phate (10  pounds  to  50  gallons).  Two  300-foot  rows  were  left  un- 
sprayed as  checks,  and  two  others  received  only  a  single  spraying 
with  the  experimental  sprayer.  The  two  rows  adjoining  the  un- 
sprayed  rows  were  held  for  comparison  with  them,  as  in  these  long 
rows  the  effect  of  any  possible  variations  in  the  soil  is  eliminated. 
Samples  of  the  soil  were  taken  at  various  places  between  the  two  un- 
sprayed  rows  and  likewise  between  the  two  sprayed  rows.  The 
analyses  of  these  soils,  given  in  Table  2  as  Nos.  637  and  638,  show 
5.19  and  5.12  per  cent,  respectively,  of  manganese  as  Mn304.  A 
comparison  of  these  analyses  of  the  soils  under  the  unsprayed  and 
sprayed  rows,  respectively,  shows  that  any  difference  between 
them  is  to  be  ascribed  to  the  spraying  treatment. 

The  effect  of  spraying  on  the  stunted  red  fruit  was  even  more 
remarkable  than  that  on  the  yellow  plants.  These  characteristic 
fruits  of  manganiferous  soils  became  normal  dark  green  and  com- 
menced a  most  vigorous  growth  within  two  or  three  weeks  after  they 
were  sprayed.  A  decided  change  in  them  could  be  noticed  within  a 
week.  If  some  of  the  iron  solution  struck  one  side  only  of  an  unripe 
fruit  this  side  became  green  first  and  made  such  growth  that  the  fruit 
soon  presented  a  ''lopsided"  appearance.  Later  the  iron  appeared 
to  be  evenly  distributed,  because  the  fruit  was  fairly  symmetrical 
when  ripe. 

Plate  III,  Figure  1,  shows  the  appearance  of  the  unsprayed  and 
sprayed  rows  on  May  19,  1916,  about  a  month  after  the  spraying  was 
done.  The  view  is  taken  looking  north  along  the  rows.  The  un- 
sprayed row  on  the  left  was  closest  to  the  camera,  but  the  great  im- 
provement in  size  and  appearance  of  the  fruit  on  the  two  sprayed 
rows  to  the  right  is  evident.  It  is  impossible  to  show  with  an  ordi- 
nary photograph  the  great  difference  in  color  which  made  the  yellow 
check  rows  in  the  green  sprayed  field  visible  at  a  long  distance. 
The  rows  which  received  one  spraying  were  quite  yellow,  but  had  a 
greenish  tinge  compared  with  the  unsprayed  rows. 

Plate  III,  Figure  2,  shows  a  view  taken  halfway  along  the  rows  look- 
ing south.  The  unsprayed  rows  on  the  right  illustrate  the  variable 
destructive  effects  of  the  manganese  soils  on  the  pineapple  plant. 
The  two  plants  in  the  right  foreground  set  small  red  fruit  which 
cracked  open  around  the  eves  and  decayed.  Some  of  the  red  fruit 
reaches  maturity  without  clecay,  but  it  is  of  very  inferior  quality. 
The  third  plant  visible  in  the  unsprayed  row  did  not  blossom  at  all 
and  was  slowly  dying  when  photographed.  The  plants  immediately 
beyond  this  suffered  the  most  serious  injury,  the  few  dying  yellow 
leaves  which  were  left  turning  brown  and  shriveling  at  the  time  the 


Bui.   52,    Hawaii    Agr.    Expt.    Station. 


Plate  II. 


Fig.   I. — Front  View  of  Sprayer  Used. 


Fig.  2. — Rear  View  of  Sprayer  Used. 


Bui.   52,    Hawaii    Agr.    Expt.    Station. 


Plate  III. 


Fig. 


I. — Main  Field  Experiment  (May  19,  1916).     Sprayed  Rows  on  Right 
Unsprayed  Rows  on  Left. 


Fig.  2.— Main  Field  Experiment  (June  30,  1916).     Sprayed  Rows  on  Left 
Unsprayed  Rows  on  Right. 


Bui.   52,    Hawaii    Agr.    Expt.   Station. 


Plate  IV. 


MAKGANESE  chlorosis  of  pineapple. 


33 


picture  was  taken.     Spraying  with  iron,  however,  will  induce  a  growth 
of  green  suckers  from  even  such  extreme  cases  as  these. 

Plate  IV  shows  characteristic  fruit  from  the  sprayed  and  the  un- 
sprayed  rows.  In  this  and  the  various  field  views  the  broad  cylin- 
drical development  and  filling  out  of  the  •'shoulder"  of  the  fruit 
underneath  the  crown  as  the  result  of  the  spraying  from  above 
should  be  noted.  This  cylindrical  development  of  the  fruit  is  veiy 
much  desired  by  the  pineapple  canneries  because  it  caused  the  least 
waste  in  sizing  for  the  cans.  As  a  result  of  this  broadening  and 
filling  out  nearly  all  of  the  fruit  from  the  sprayed  rows  was  classed  as 
"first,"  or  Xo.  I,6  while  most  of  the  elongated  fruit  from  the  un- 
sprayed  rows,  even  in  the  heavier  weights,  had  to  be  classed  as 
"seconds."  or  No.  2,  the  value  of  which  per  ton  is  reckoned  as  about 
three-fifths  that  of  Xo.  1  fruit. 

DISCUSSION  OF  RESULTS. 

During  June,  July.  August,  and  September  trips  were  made  once 
a  week  or  oftener  to  harvest  the  fruit  as  it  ripened.  After  the  crown 
and  stem  were  removed  the  ripe  pineapple  fruit  was  weighed  accu- 
rately to  ounces,  and  its  diameter  was  carefully  measured.  The 
weight  of  each  fruit  and  its  diameter  were  entered  on  a  large  chart 
according  to  the  position  of  the  bearing  plant  in  the  row.  Where  no 
fruit  was  produced  the  condition  of  the  plant  was  noted  in  the  chart. 
Each  fruit  was  classified  according  to  its  diameter  as  Xo.  1  or  Xo.  2. 
Where  a  few  fruits  had  been  removed  from  the  sprayed  rows  before 
harvesting,  the  plants  were  credited  with  the  average  of  the  nearest 
fruits.  A  short  summary  of  the  yields  on  the  sprayed  and  unsprayed 
rows  is  given  in  Table  16. 

Table  16. — Results  of  spraying  pineapple  plants  on  highly  manganiferous  soils  with 

iron  sulphate  solutions.0 


Unsprayed 
rows. 

Rows  re- 
ceiving 

single 
spraying. 

Rows  re- 
ceiving full 
iron  spray 
treatment 

in  April. 

Plants  from  which  fruit  was  harvested _.     .  . 

Xumber. 
108 

Xumber. 
151 
5 
1 

Xumber. 
244 

Plants  hearing  fruit  too  young  to  harvest 

9 

Plants  blossoming 

Plants  starting  to  blossom . 

3 

11 
36 

Plants  dead .  _ 

31 
101 

57 

Plants  with  fruit  cracked  open  and  decaved 

81 

62 

..... 

Verv  vellow  plants  giving  no  evidence  of  blossoms 

Total 

300 

300 

300 

pounds.. 

do.... 

Total  weight  of  harvested  fruit 

Average  weight  of  fruits.  ...  __     .  ..     

3101 
2| 

10.H 

39 
69 
36.1 

431-rf 

.'" 
151 
75 
76 
49.6 

7741 
3f5 

Fruits  harvested...  ... .. 

244 

Fruits  classed  as  "first"  or  Xo.  1 

Fruits  classed  as  "second"  or  Xo.  2 

214 
30 

Fruits  classed  as  Xo.  1 

per  cent.. 

pounds.. 

_...:. .do.... 

87.7 

Weight  of  Xo.  1  fruit.. 

Weight  of  Xo.  2  fruit 

128H 
181-rV 

250A 
181* 

70OrV 

74-rV 

do.... 

Total  weight  of  fruit 

310| 

43  Iff 

774f 

6  Cannery  classification  by  diameter,  fruits  having  a  diameter  above  4f  inches  being  classed  as  Xo.  1, 
and  those  having  a  diameter  of  4i  to  4f  inches  as  Xo.  2. 
°  These  results  are  for  adjoining  double  300-foot  rows,  in  each  of  which  there  were  150  plants. 


34  BULLETIN    52,    HAWAII   EXPERIMENT   STATION.- 

Table  16  shows  the  practical  value  of  the  iron-spraying  treatment, 
even  though  it  was  not  applied  until  after  the  plants  had  suffered 
during  the  greater  part  of  their  growing  period  from  manganese- 
induced  chlorosis.  ^Plants  starting  to  blossom"  refers  to  the  green, 
healthy  plants  on  the  sprayed  rows  whose  flowering  had  been  delayed 
by  the  effects  of  the  manganiferous  soil  and  in  which  the  blossoms 
was  just  appearing.  Only  fruit  that  was  completely  destroyed  is 
classed  under  " Plants  with  fruits  cracked  open  and  decayed." 
Fruit  which  showed  only  a  few  spots  of  decay  was  credited  with  full 
weight,  although  only  a  part  of  it  could  be  used.  No  decay  was  seen 
on  the  rows  of  fruit  which  received  the  full  number  of  sprayings. 

Although  the  increase  in  the  average  weight  of  the  fruit  was  not 
as  large  as  would  be  estimated  from  its  appearance  in  the  field,  the 
increase  in  diameter  and  size  of  the  fruit  on  sprayed  rows,  as  men- 
tioned above,  caused  nearly  all  of  them  to  class  as  No.  1,  the  value 
of  which  is  considered  nearly  twice  that  of  the  No.  2. 

PRACTICAL  ADVICE  REGARDING  THE  TREATMENT. 

Although  beneficial  results  from  an  iron-spray  treatment,  as 
described  above,  were  obtained  with  pineapple  plants  which  had 
suffered  during  the  greater  part  of  their  growth  from  lack  of  iron, 
such  late  spraying  is  not  advised. 

Sprayings  at  intervals  of  one  to  four  months,  depending  upon  the 
condition  of  the  plants,  are  recommended  for  young  crops.  The 
color  and  general  appearance  of  the  plants  should  be  used  as  an 
indication  of  their  need  of  spraying.  The  plants  should  be  sprayed 
whenever  there  is  any  indication  of  yellowing  or  of  fading  vigor,  it 
being  the  idea  to  give  them  sufficient  iron  to  keep  them  green  and 
healthy.  The  exact  number  and  times  of  sprayings  can  not  be 
specified  exactly  for  varying  local  conditions,  but  the  most  beneficial 
treatment  for  particular  fields  can  easily  be  ascertained  if  the  color 
and  general  vigor  of  the  plant  are  used  as  indicators. 

The  most  economical  and  effective  method  of  supplying  the  iron 
sulphate  (copperas)  appears  to  be  that  of  spraying  the  plants  with  a 
fairly  strong  solution  in  the  form  of  a  fine  mist.  An  approximate 
6  per  cent  solution  (25  pounds  of  copperas  to  50  gallons  of  water)  has 
been  found  very  effective  in  restoring  the  green  color  without  seriously 
burning  the  plants.  No  injurious  effects  were  noticed  even  when 
an  application  of  about  14  gallons  of  an  8  per  cent  solution  per  acre 
was  used  in  the  fine  spray  on  young  plants.  This  solution  may  have 
to  be  weakened  when  a  heavier  spray  is  applied  to  young  plants. 
Any  form  of  sprayer  or  even  a  hand  sprinkler  may  be  used  provided 
it  applies  about  10  pounds  per  acre  of  the  copperas  in  solution. 

From  3  to  4  per  cent  (12  to  16  pounds  per  50  gallons)  of  ammonium 
sulphate  in  the  iron  sulphate  seems  to  give  good  results.  It  should 
be  remembered  that  only  one  of  the  elements  necessary  for  growth 
is  supplied  when  the  plant  is  sprayed  with  iron.  Soluble  phosphates 
and  nitrogen  as  sulphate  of  ammonia  or  in  organic  form  are  recom- 
mended for  use  when  commercial  fertilizers  are  to  be  applied  to  the 
soils.  Potash  is  not  as  necessary  in  fertilizer  formulas  for  these  as 
for  other  soils  because  manganese  soils  are  fairly  rich  in  potash  as 
well  as  in  phosphoric  acid  and  nitrogen  and  should,  therefore,  prove 
fertile  when  iron  is  applied  to  the  plants.     Cannery  ash,  which  is 


MANGANESE    CHLOROSIS   OF    PINEAPPLE.  35 

used  for  its  potash,  should  be  treated  with  acids  when  applied  to 
manganese  soils.  Nitrate  of  soda  should  not  be  applied  to  manga- 
nese soils  because  of  its  injurious  effects.  The  addition  of  humus- 
forming  materials  to  the  soils  is  emphasized  in  every  system  of 
agricultural  practice.  Such  materials  are  of  especial  value  to  the 
soils  of  Hawaii  which  are  of  heavy  clay  character  and  have  a  tendency 
to  puddle.  It  is  recommended  that  stable  manure  or  other  humus- 
forming  material  be  used  if  it  can  be  applied  at  a  a  reasonable  cost. 
Leguminous  green  manuring  crops  are  very  valuable.7 

Pineapple  plants  should  be  sprayed  with  iron  sulphate  solution 
regardless  of  the  kind  of  preparation  given  the  manganese  soils. 
No  method  of  preparation  of  the  highly  manganiferous  soils  so  far 
tested  allows  the  plant  to  absorb  sufficient  iron  and  the  iron  spray 
should  be  applied  as  soon  as  any  signs  of  yellowing  appear. 

GENERAL  SUMMARY  AND  CONCLUSIONS. 

A  review  is  given  of  previous  investigations  on  manganese.  No 
conclusive  proof  is  furnished  in  these  of  any  stimulating  action  due 
primarily  to  manganese.  The  chlorotic  effect  found  with  higher 
concentrations  of  manganese  has  generally  been  attributed  to  an 
indefinite  u toxic  effect'  of  the  manganese  or  to  " manganese  poison- 
ing.'' It  was  not  proved  in  these  previous  investigations  that 
manganese  causes  a  deficiency  of  iron  in  the  plant  or  that  supplying 
iron  will  cure  manganese  "poisoning." 

The  writer  shows  that  the  manganese  of  the  highly  manganiferous 
Hawaiian  soils  is  present  mainly  in  the  dioxid  form;  that  hydrogen- 
ion  determinations  indicate  these  soils  to  be  acid;  and  that  calcium 
carbonate  is  absent. 

A  series  of  experiments  were  conducted  with  rice  grown  in  nutrient 
solutions  to  determine  the  effect  of  manganous  sulphate  and  manga- 
nese dioxid  on  growth  where  various  amounts  of  iron  were  supplied 
to  the  nutrient  solution  from  various  sources.  Preliminary  experi- 
ments indicated  that  the  effect  of  manganese  depends  largely  on  the 
amount  of  iron  supplied  by  the  solution. 

When  the  nutrient  solution  contained  a  normal  amount  of  iron, 
manganous  sulphate  and  manganese  dioxid  caused  a  strong  chlorosis 
and  a  severe  depression  in  growth.  This  chlorosis  was  overcome 
when  the  leaves  were  dipped  in  solutions  of  iron  salts  or  the  amount 
of  iron  in  the  nutrient  solution  was  excessively  increased. 

This  manganese-induced  chlorosis  was  thus  shown  to  be  due  to  a 
depression  in  the  assimilation  of  iron  or  to  a  deficiency  of  iron  in  the 
plant.  The  previous  results  and  conclusions  of  the  writer  concerning 
the  manganiferous  Hawaiian  soils  are  thus  confirmed. 

Manganese-induced  chlorosis  is  altogether  distinct  from  lime- 
induced  chlorosis,  due  to  calcium  carbonate,  since  manganese-induced 
chlorosis  can  and  usually  does  occur  under  acid  conditions.  Manga- 
nese and  calcium  carbonate  can  each  produce  an  additive  chlorotic 
effect  in  the  presence  of  the  other. 

No  evidence  was  found  to  show  that  manganese  exerts  any  stimu- 
lating effect  on  plant  growth.     With  nutrient  solutions  containing 

7  The  value  of  the  different  legumes  is  discussed  in  Hawaii  Sta.  Press  Bui.  52,  Comparative  value  of 
legumes  as  green  manure. 


36  BULLETIN    52,    HAWAII    EXPERIMENT    STATION. 

an  excessive  amount  of  iron,  manganese  dioxid,  by  removing  some 
of  this  harmful  iron,  caused  an  increase  in  growth. 

Sodium  hydroxid  titration  curves  are  given  for  ferric  chlorid  and 
ferrous  sulphate.  Determination  of  the  solubilities  of  iron  at  different 
hydrogen-ion  concentrations  show  that  ferric  iron  is  completely 
precipitated  while  the  solution  is  still  strongly  acid,  and  that  ferrous 
iron  is  soluble  under  fairly  alkaline  conditions. 

This  difference  in  solubility  of  ferric  and  ferrous  iron  affords  an 
explanation  of  the  manner  in  which  manganese  induces  chlorosis. 
Manganese  dioxid,  either  present  as  such  or  formed  from  manganous 
salts,  would  keep  the  iron  present  oxidized  to  the  much  more  diffi- 
cultly available  ferric  form. 

A  description  is  given  of  field  experiments  in  which  solutions  of 
iron  salts  were  applied  to  the  leaves  of  pineapple  plants  on  the  manga- 
niferous  Hawaiian  soils.  This  treatment  effected  immediate  cure 
of  the  " toxic  effects"  of  manganese  and  induced  a  normal  growth. 
The  treatment  was  quickly  adopted  by  all  the  pineapple  growers 
having  manganiferous  soils  and  is  now  being  regularly  used  on 
considerably  over  half  of  the  Hawaiian  pineapple  fields. 

LITERATURE  CITED. 

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1902.  On  the  physiological  influence  of  manganese  compounds  on 
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177-185. 

(2)  1904.  On  the  practical  application  of  manganous  chlorid  in  rice  culture. 

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(4)  Bernardini,  L. 

1910.  Funzione  del  manganese  nella  concimazione.  Staz.  Sper.  Agr. 
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(5)  Bertrand,  G. 

1897.  Sur  rintervention  du  manganese  dans  les  oxydations  provoquees 
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(8)  Brenchley,  W.  E.  (Miss). 

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(9)  Brown,  P.  E.,  and  G.  A.  Minges. 

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1918.  The  development  of  soluble  manganese  in  acid  soils  as  influenced 

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MANGANESE    CHLOROSIS    OF    PINEAPPLE.  37 

(14)  Gile,  P.  L. 

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